The Science of Healthy Hair, Hair Loss and How to Regrow Hair

Welcome to the Huberman Lab podcast, where we discuss science and science-based tools for everyday life.

欢迎来到休伯曼实验室播客，我们在这里讨论科学和基于科学的日常生活工具。

I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine.

我是安德鲁·胡伯曼，斯坦福大学医学院神经生物学和眼科教授。

Today we are discussing hair.

今天我们讨论的是头发。

Hair is a topic that occupies the minds of many people.

头发是很多人都关心的话题。

There are people that are losing their hair and want to halt or reverse that loss of hair, and today we will talk about all the ways that science has taught us we can slow or even reverse hair loss.

有些人正在脱发，并希望阻止或逆转脱发，今天我们将讨论科学告诉我们的可以减缓甚至逆转脱发的所有方法。

I confess that researching today's topic was a particular joy for me, not because I'm obsessed with hair, mine or the hair of others, but because hair turns out to be fascinating from the perspective of cellular biology and stem cells, which is a topic that I've long been interested in, and that for much of my career I've focused on in the context of development.

我承认，研究今天的主题对我来说是一种特别的乐趣，不是因为我痴迷于头发，无论是我的头发还是别人的头发，而是因为从细胞生物学和干细胞的角度来看，头发是令人着迷的，这是我长期以来感兴趣的一个主题，并且在我职业生涯的大部分时间里，我都专注于发展的背景。

So when your brain and your nervous system develop, it develops from a small batch of cells that turns into many, many trillions of cells, and it does that by cell replication, something that we call the cell cycle, and we'll talk a little bit about this and so-called mitosis today.

因此，当你的大脑和神经系统发育时，它会从一小批细胞发展成许多、数万亿个细胞，它是通过细胞复制来实现的，我们称之为细胞周期，今天我们将讨论一下这个和所谓的有丝分裂。

I promise not to get into too much detail, but what makes hair so very interesting from a biological standpoint is that every hair, every single individual strand of hair, has its own little stem cell niche, meaning its own little pocket down there in the follicle in which specific stem cells give rise to those hairs for different durations of time, depending on the hair, where it is on your body, et cetera.

我保证不会讲太多细节，但从生物学的角度来看，头发如此有趣的原因在于，每根头发，每一根单独的头发，都有自己的小干细胞生态位，这意味着毛囊中有自己的小口袋，特定的干细胞在不同的时间内产生这些头发，具体时间取决于头发、它在你身体上的位置等。

So for instance, the hairs on your head will undergo ongoing growth for four to six or even eight years.

例如，你头上的头发将持续生长四到六年甚至八年。

So were you to not cut your hair, it would continue to grow.

所以，如果你不剪头发，它还会继续生长。

One single hair would continue to grow.

一根头发会继续生长。

I guess we could say all the hairs will continue to grow for up to eight years.

我想我们可以说所有的毛发都会继续生长长达八年。

That is very different from, for instance, your eyebrows, which have a much shorter period of hair growth, lasting on the order of months.

例如，这与眉毛有很大不同，眉毛的毛发生长周期要短得多，可持续数月左右。

That's why you don't see people with eyebrows that extend down to their waist, but you can see people with hair on their head that extends down to their waist if they don't cut it.

这就是为什么你看不到眉毛长到腰部的人，但你可以看到头上的头发如果不剪的话就长到腰部了。

Now, that discrepancy illustrates for us just how incredible hair follicles and the stem cells that reside within hairs are, and their enormous potential to give rise to these things that we call hairs, which are simply proteins of varying length.

现在，这种差异向我们说明了毛囊和毛发内的干细胞是多么令人难以置信，以及它们产生我们称之为毛发的东西的巨大潜力，这些东西只是长度不同的蛋白质。

So today we are going to address what determines the length of a hair, or rather what determines how long a hair continues to grow before it ceases growing and eventually falls out.

因此，今天我们将讨论决定头发长度的因素，或者更确切地说，决定头发在停止生长并最终脱落之前继续生长多长时间的因素。

We're going to talk about what regulates those stem cells, what allows them to continue to produce hair or cease producing hair.

我们将讨论是什么调节这些干细胞，是什么让它们继续产生头发或停止产生头发。

And as we do that, you will learn all the biology in clear, simple terms, regardless of your background, that will really set the stage for understanding what we'll also talk about, which is how to slow hair loss or halt hair loss entirely, or even reverse hair loss.

当我们这样做时，无论您的背景如何，您都将以清晰、简单的术语学习所有生物学知识，这将为理解我们还将讨论的内容奠定基础，即如何减缓脱发或完全停止脱发，甚至逆转脱发。

So we will talk about hormone-related hair loss in both men and women, we will talk about some of the mechanical and stress-related influences on hair loss, and we will talk about the chemical and mechanical approaches to halting and reversing hair loss.

因此，我们将讨论男性和女性与激素相关的脱发，我们将讨论一些机械和压力相关的脱发影响，我们将讨论阻止和逆转脱发的化学和机械方法。

Everything from minoxidil to dutasteride, to ketoconazole, to microneedling, to thyroid, estrogen, IGF-1 pathways.

从米诺地尔到度他雄胺，到酮康唑，到微针，到甲状腺、雌激素、IGF-1 途径。

Again, all made very clear, regardless of whether or not you have a background in biology or not.

同样，无论您是否有生物学背景，一切都非常清楚。

I will also dispel some of the common myths about balding and hair replacement.

我还将消除一些关于秃顶和植发的常见神话。

If you've heard, for instance, that you inherit your patterns of balding from your mother's father, that is not true, although it is true that you do inherit certain genes that influence whether or not you have a predisposition to balding in particular parts of your head, and believe it or not, even in particular parts of your body.

例如，如果你听说你从你的父母那里继承了秃顶模式，那是不正确的，尽管你确实继承了某些基因，这些基因会影响你头部特定部位是否有秃顶的倾向，无论你相信与否，甚至是你身体的特定部位。

But it is not the case that you can simply find a photo of your mother's father, say at age 50 or age 60 or 75, and determine whether or not you'll have the exact same pattern of hair loss.

但事实并非如此，你可以简单地找到一张你母亲的父亲（比如 50 岁、60 岁或 75 岁）的照片，然后确定你是否会出现完全相同的脱发模式。

So that's a myth that I'd like to dispel right here and now.

所以这是一个我想在此时此地消除的神话。

And I will dispel some of the other myths about hair loss, hair replacement, and hair regrowth as well.

我还将消除一些关于脱发、头发替换和头发再生的其他神话。

Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford.

在开始之前，我想强调一下，这个播客与我在斯坦福大学的教学和研究角色是分开的。

It is, however, part of my desire and effort to bring zero cost to consumer information about science and science-related tools to the general public.

然而，我的愿望和努力的一部分是向公众提供有关科学和科学相关工具的零成本消费者信息。

In keeping with that theme, I'd like to thank the sponsors of today's podcast.

为了与这个主题保持一致，我要感谢今天播客的赞助商。

There is so much NFL on ESPN right now.

ESPN 上现在有很多 NFL 节目。

Monday Night Football, plus pre-game and post-game.

周一橄榄球之夜，以及赛前和赛后。

NFL Live, NFL Prime Time.

NFL 直播，NFL 黄金时间。

Everything you need to stay on top of every game, every week.

每周掌握每场比赛所需的一切。

Unbelievable.

难以置信。

And now NFL Network is on the ESPN app.

现在 NFL Network 已登陆 ESPN 应用程序。

More football, more coverage, more ways to watch.

更多足球比赛、更多报道、更多观看方式。

Football's on all season long on ESPN and streaming on the ESPN app.

ESPN 提供整个赛季的足球赛事直播，并通过 ESPN 应用程序进行直播。

Okay, let's talk about hair, and in researching this episode by talking to experts in the biology of hair and the stem cells that exist in all of us that give rise to our hair growth and the pigmentation in our hair, and in talking to experts who understand how to halt and even reverse hair loss, that there is a tremendously interesting biology surrounding hair.

好吧，让我们谈谈头发，在研究这一集时，我们与头发生物学和我们所有人体内存在的导致头发生长和头发色素沉着的干细胞的专家交谈，并与了解如何阻止甚至逆转脱发的专家交谈，发现围绕头发有一个非常有趣的生物学。

But there's also an incredible psychology around hair.

但头发也有一种令人难以置信的心理。

In fact, most people who experience even marginal hair loss undergo pretty severe anxiety.

事实上，大多数经历过轻微脱发的人都会经历相当严重的焦虑。

Now, I confess this is not something I can relate to.

现在，我承认这不是我能理解的事情。

I am losing my hair in certain places.

我的某些地方开始脱发。

I'm 47 years old.

我今年47岁了。

I've got a couple patches up front where there's very minimal hair.

我前面有几个补丁，头发很少。

I think that, as we'll later learn in this episode, reflects a higher density of DHT, dihydrotestosterone, receptors at that particular location as opposed to elsewhere on my scalp.

我认为，正如我们稍后将在本集中了解到的那样，这反映了该特定位置的 DHT（二氢睾酮）受体密度高于头皮其他地方。

But keeping my hair is not something that I've fretted about much of my life.

但保留头发并不是我一生中大部分时间都担心的事情。

And yet, as I was researching this episode, I remembered an anecdote from my childhood where My father told me, and I think it was because I was stressing about something, and I was trying to get to sleep, and he said, "Don't stress.

然而，当我研究这一集时，我想起了我父亲告诉我的童年轶事，我认为这是因为我对某事感到压力，而我正试图入睡，他说：“不要压力。

Calm down, and here's why.

冷静下来，这就是原因。

If you stress too much, it can actually make your hair fall out.

如果你压力太大，实际上会让你的头发脱落。

In fact, I have a cousin who lay down one night stressed and woke up the next morning, and all of his hair was on his pillow." And I'll never forget that story.

事实上，我有一个表弟，他一晚上压力很大地躺着，第二天早上醒来，所有的头发都在枕头上。”我永远不会忘记那个故事。

I think he was trying to get me to stress less.

我认为他是想让我减轻压力。

I don't know if that story made me stress less or not.

我不知道这个故事是否让我减轻了压力。

But in any event, I don't know that that story's true.

但无论如何，我不知道那个故事是真的。

I'm not going to challenge the authenticity of that story.

我不会质疑这个故事的真实性。

I didn't have a chance to reach out to my father and ask him to verify or not.

我没有机会联系我父亲并请他证实与否。

But as we'll soon learn, it is true that our psychological well-being can impact both the coloration, or lack thereof, and the growth rates of our hair.

但正如我们很快就会了解到的那样，我们的心理健康确实会影响头发的颜色（或缺乏颜色）以及头发的生长速度。

That's a real thing.

这是真实的事情。

And the reverse is also true, which is that as hair starts to thin or fall out or change color, many people experience intense anxiety or even depression.

反之亦然，随着头发开始稀疏、脱落或变色，许多人会经历强烈的焦虑甚至抑郁。

This was not something I was really aware of.

我并没有真正意识到这一点。

Perhaps that's just because I've always kept my hair pretty short anyway.

也许这只是因为我一直把头发留得很短。

I always assumed that if my hair started to really fall out, I would just shave my head.

我一直以为如果我的头发开始真正脱落，我就会剃光头。

But that's me, and that's not most people out there.

但这就是我，而不是大多数人。

I think most people would loathe to lose their hair.

我想大多数人都不愿意脱发。

And in fact, given the enormous number, probably up in the high billions of dollars and euros and other currency, of course, that people invest in trying to halt or reverse their hair loss, it's clear that hair is very, very important to people.

事实上，考虑到人们为了阻止或扭转脱发而投入的资金数量巨大，当然可能高达数十亿美元、欧元和其他货币，很明显，头发对人们来说非常非常重要。

What we know is that by age 50, approximately 50% of all men and women will have experienced significant enough hair loss that they start to notice it.

我们知道，到 50 岁时，大约 50% 的男性和女性都会经历严重的脱发，以至于他们开始注意到这一点。

And a large percentage, up to 85% of those people, will experience some sort of anxiety that leads them to go out and try and either halt or reverse that hair loss.

其中很大一部分人（高达 85%）会经历某种焦虑，导致他们出去尝试阻止或扭转脱发。

Now, why at age 50?

现在，为什么是50岁呢？

Well, an important point arises from that, which is that the hair loss is not occurring between the 49th and 50th birthday.

那么，重要的一点是，脱发不会发生在 49 岁到 50 岁生日之间。

Hair loss is ongoing from about age 30 to age 50.

脱发从30岁左右持续到50岁。

It's only by age 50, however, that about 50% of people out there start to notice that hair loss, and this is typically because they'll be in a bathroom or looking in a mirror and the lighting will be bright enough that it permeates the sort of outer boundary of their hair, and they'll notice that their hair is thinning in a particular location.

然而，只有到了 50 岁，大约 50% 的人才开始注意到脱发，这通常是因为他们在浴室或照镜子时，灯光足够亮，渗透到头发的外缘，他们会注意到特定位置的头发正在稀疏。

That's usually how this sort of thing happens.

这种事情通常就是这样发生的。

So again, our psychological states can impact our patterns of hair growth or loss, and of course, patterns of hair growth, but more typically hair loss and hair graying, can really impact psychological state.

再说一次，我们的心理状态会影响我们的头发生长或脱发模式，当然，头发生长模式，但更常见的是脱发和头发变白，确实会影响心理状态。

So this is a subject that people take intense interest in, and today we're going to talk about how hair normally grows, why it grows at the rate and for the duration that it happens to.

所以这是一个人们非常感兴趣的话题，今天我们将讨论头发通常是如何生长的，为什么它会以这样的速度和持续时间生长。

And then as we talk about ways to intervene with that hair loss, those biological mechanisms will come up because they really provide a nice framework for explaining why certain treatments work more or less well, or why certain treatments might have certain side effects or total lack of side effects.

然后，当我们谈论干预脱发的方法时，这些生物机制就会出现，因为它们确实提供了一个很好的框架来解释为什么某些治疗或多或少有效，或者为什么某些治疗可能有某些副作用或完全没有副作用。

It will also highlight a really key theme that will come up several times in today's podcast, which is that there are both mechanical and chemical approaches to slowing and reversing hair loss.

它还将强调一个真正关键的主题，这个主题将在今天的播客中多次出现，即有机械和化学方法来减缓和逆转脱发。

Mechanical approaches would be things as simple as massaging the scalp, but mechanical changes to the scalp can cause either hair loss or facilitate hair growth.

机械方法就像按摩头皮一样简单，但头皮的机械变化可能会导致脱发或促进头发生长。

This is why things like microneedling are so prominent in the context of trying to reverse hair loss.

这就是为什么像微针这样的技术在试图扭转脱发的过程中如此重要。

But again, there are also chemical approaches to trying to halt or reverse hair loss.

但同样，也有化学方法可以尝试阻止或逆转脱发。

And this relates to the fact that the hair growth itself is strongly regulated by hormones such as estrogen, thyroid hormone, insulin-like growth factor, and that other hormones, in particular the androgens, so things like testosterone, but mainly its derivatives like dihydrotestosterone, are very much involved in setting the stage for hair growth by controlling how big or small that pool of stem cells that gives rise to hair growth is.

这与头发生长本身受到雌激素、甲状腺激素、胰岛素样生长因子等激素的强烈调节有关，而其他激素，特别是雄激素，例如睾酮，但主要是其衍生物，如二氢睾酮，通过控制引起头发生长的干细胞池的大小，在很大程度上参与了头发生长的准备。

So if any of the terms I just used are confusing to you, don't worry.

因此，如果我刚才使用的任何术语让您感到困惑，请不要担心。

I will make all of those very clear in a moment.

我稍后会将所有这些都说清楚。

It's actually all pretty straightforward and simple.

实际上这一切都非常简单明了。

And so I'd like to just start by talking about what hair is, how it grows, why it stops growing, and why hair normally falls out.

所以我想首先谈谈什么是头发、它是如何生长的、为什么它停止生长以及为什么头发通常会脱落。

Let's talk about the biology of hair, and in doing so, I also want to talk about stem cells.

让我们谈谈头发的生物学，在此过程中，我还想谈谈干细胞。

Now, keep in mind that when you hear the word stem cells, you probably like most people, think about the sorts of cells that people are getting injected into their face to get rid of wrinkles or give them new skin or to give them more hair if it's injected in the scalp or into a joint to repair a joint or a muscle.

现在，请记住，当您听到干细胞这个词时，您可能会像大多数人一样，想想人们注射到脸上以消除皱纹或赋予新皮肤或给予更多头发（如果将其注射到头皮或关节中以修复关节或肌肉）的细胞类型。

Those stem cells are what we call exogenous stem cells, exogenous, meaning from outside the body.

那些干细胞就是我们所说的外源干细胞，外源的，意思是来自体外的。

The stem cells that we're going to talk about today are so-called endogenous stem cells, cells that we all make that can give rise to other cells.

我们今天要讨论的干细胞是所谓的内源性干细胞，我们所有人都会产生可以产生其他细胞的细胞。

And that's really the definition of a stem cell.

这确实是干细胞的定义。

Stem cells are present in all of us from the very beginning of life.

干细胞从生命之初就存在于我们所有人体内。

So when sperm meets egg, that cell, which we think of as the egg, starts to duplicate.

因此，当精子遇到卵子时，我们认为是卵子的细胞就开始复制。

It incorporates the DNA from the sperm and the egg, of course.

当然，它融合了精子和卵子的 DNA。

It starts to duplicate, and then those cells give rise to more cells and more cells, and the ability of all those cells to replicate and create more cells are because those cells really are stem cells.

它开始复制，然后这些细胞产生越来越多的细胞，所有这些细胞能够复制和创造更多细胞的能力是因为这些细胞确实是干细胞。

Now, at some point, we are a completed body plan, as the biologists say.

现在，正如生物学家所说，在某个时刻，我们的身体计划已经完成。

We end up with a brain and a spinal cord and limbs and fingers and livers and guts, and all the things that we need in order to be a functioning human being, even though we're a baby at that time.

我们最终有了大脑、脊髓、四肢、手指、肝脏和内脏，以及我们成为一个正常人所需的所有东西，即使我们当时还是个婴儿。

We haven't grown up.

我们还没有长大。

We have all the bits that we're going to have for our entire life.

我们拥有一生中将拥有的所有东西。

At that point, many of the stem cell populations disappear.

那时，许多干细胞群就会消失。

For instance, past puberty, and probably earlier, you don't get many more new brain cells.

例如，青春期过后，甚至可能更早，你不会获得更多的新脑细胞。

You get a few, but you don't get many more new brain cells because the brain doesn't have many stem cell populations, whereas other organs in your body maintain little pockets of stem cells, or in some cases, many stem cells that can give rise to more and more of that tissue across the lifespan.

你会得到一些，但你不会得到更多的新脑细胞，因为大脑没有很多干细胞群，而你身体的其他器官则维持着一小部分干细胞，或者在某些情况下，有许多干细胞，这些干细胞可以在整个生命周期中产生越来越多的组织。

And hair is one such tissue.

头发就是这样的一种组织。

So if we take a look at hair, what we find is that indeed, there are these things that we call hairs, but there are also stem cells, and those stem cells are actually what give rise to the hairs that we see on the head of our scalp or that we see on the surface of our body.

因此，如果我们观察头发，我们会发现确实有一些我们称之为头发的东西，但也有干细胞，而这些干细胞实际上是产生我们在头皮上或身体表面看到的头发的原因。

So right off the bat, you should know that every single hair that you have is there because you have a stem cell population that is giving rise to that particular hair.

因此，您应该立即知道您拥有的每一根头发都在那里，因为您有一个正在产生特定头发的干细胞群。

So let's take a step back, or rather, I should say, let's zoom in on one hair and the stem cell population that gives rise to that hair, because in doing so, you're going to learn all the different components that you can tap into if your goal is to halt the loss of hairs or to replace hairs that have already been lost.

因此，让我们退后一步，或者更确切地说，我应该说，让我们放大一根头发和产生该头发的干细胞群，因为这样做时，如果您的目标是阻止头发脱落或替换已经脱落的头发，您将了解可以利用的所有不同成分。

Okay, so if we were to just zoom in at the level of one hair, what you would find is that that hair has what typically is called a hair root, so that's the portion below the skin.

好的，如果我们只放大一根头发的水平，您会发现该头发具有通常所说的发根，即皮肤下方的部分。

And when we say below the skin, it means that it dives down into a narrow trench, which is in the so-called epidermis, which is this outer layer of skin.

当我们说在皮肤下面时，这意味着它潜入一条狭窄的沟槽，该沟槽位于所谓的表皮中，即皮肤的外层。

It also has a shaft.

它还有一个轴。

The shaft is the part that grows out above the skin.

轴是在皮肤上方生长的部分。

So what you see on somebody's head or you see on their arm, or when you see an eyebrow, you're seeing the shaft of the hair.

所以你在某人的头上或他们的手臂上看到的，或者当你看到眉毛时，你看到的是头发的干。

The root, of course, goes below the skin.

当然，根部是在皮肤下面的。

What most people don't realize, however, is that down at the base of the root, there's actually a little cave, a little pocket.

然而，大多数人没有意识到，在根部的底部，实际上有一个小洞穴，一个小口袋。

So if you were to look at this, it would look like a little bulb, a little round area with a bunch of stuff in it right below the root.

所以如果你看这个，它看起来像一个小球茎，一个小圆形区域，在根部正下方有一堆东西。

And within that little cave, there are stem cells.

那个小洞穴里有干细胞。

There are populations of cells that have the ability to divide.

有些细胞群具有分裂能力。

We call this mitosis.

我们称之为有丝分裂。

It's a process by which cells can actually divide and take DNA with them, and then give rise to other cells.

在这个过程中，细胞实际上可以分裂并携带DNA，然后产生其他细胞。

We call those cells that divide and move out, we call those daughter cells.

我们将那些分裂并移出的细胞称为子细胞。

We call the cells that give rise to them progenitor cells.

我们将产生它们的细胞称为祖细胞。

But they are effectively stem cells that give rise to these, what we call daughter cells.

但它们实际上是产生这些子细胞的干细胞。

Those daughter cells then become the various types of cells that make up the hair.

这些子细胞随后变成构成头发的各种类型的细胞。

So when you see a hair, you're not seeing something that grows throughout the lifespan.

因此，当你看到一根头发时，你看到的并不是在整个生命周期中不断生长的东西。

You're seeing something that's going to be born down there in that little cave, then is going to grow.

你会看到一些东西会在那个小洞穴里诞生，然后会成长。

It's actually going to stack up on top of itself, and that's because hairs are made up of a protein called keratin.

它实际上会堆积在自身之上，这是因为毛发是由一种称为角蛋白的蛋白质组成的。

There are a bunch of different kinds of keratins, depending on what kind of hair you're looking at.

角蛋白有很多种，具体取决于您所观察的头发类型。

But these are little proteins that stack up on top of one another, and they're structured in a way that makes them pretty darn durable.

但这些都是相互堆叠的小蛋白质，它们的结构方式使它们非常耐用。

It's possible, of course, to pull a hair out, but if you've ever tried to tear a hair, in particular a thick hair, like one from the face or even one off the top of your head, it's actually a pretty tensile, strong, little thing.

当然，拔一根头发是可能的，但如果你曾经试图撕下一根头发，特别是一根浓密的头发，比如脸上的一根，甚至头顶上的一根，它实际上是一个相当拉力的、强大的小东西。

And that's because keratins stack up on top of one another and bind to one another with a really strong bond.

这是因为角蛋白彼此堆叠并以非常牢固的键相互结合。

So what you end up with is a bunch of proteins stacked up on top of one another, and that's the actual hair.

所以你最终得到的是一堆蛋白质堆叠在一起，这就是真正的头发。

Okay, so we've got the hair shaft, the hair root, and then we've got the stem cells down there in that pocket that give rise to the various cells that make up the actual hair.

好的，我们有了毛干、发根，然后我们在那个口袋里找到了干细胞，它们产生了构成真正头发的各种细胞。

We also have down there in that little cave, which by the way, is actually called the hair bulb, if you really want to know the technical name, because it's shaped like a bulb.

我们在下面的那个小洞穴里也有，顺便说一句，如果你真的想知道它的技术名称的话，它实际上被称为毛球，因为它的形状像一个球茎。

We have not just stem cells, but we have cells that give rise to the pigment of the hair, that create what's called melanin.

我们不仅拥有干细胞，还拥有产生头发色素的细胞，从而产生所谓的黑色素。

Now, some people have very blonde hair, very light hair.

现在，有些人有非常金色的头发，非常浅色的头发。

Some people have darker hair.

有些人的头发较黑。

But everybody, unless they have what's called the albino mutation, where the hairs are truly white, they lack all melanin, and this is a pretty rare condition, although it does happen.

但每个人，除非他们有所谓的白化突变，即头发真正变白，否则他们都缺乏黑色素，这是一种非常罕见的情况，尽管它确实发生了。

Most people have some degree of melanin in their hairs because there are little pockets of melanin-producing cells, melanin's just a protein, that essentially gets injected into the keratin, into the hair, and it gives it its darker color.

大多数人的头发中都含有一定程度的黑色素，因为产生黑色素的细胞很少，黑色素只是一种蛋白质，本质上被注入角蛋白、头发中，并赋予头发较深的颜色。

Now, there are a couple other components about the hair that you need to know about, especially if you're interested in reversing hair loss or reversing graying of hair.

现在，您还需要了解有关头发的其他一些组成部分，特别是如果您对扭转脱发或扭转头发变白感兴趣的话。

One of those components is a little gland.

这些组件之一是一个小腺体。

So next to every hair root, within the dermal layer of the skin, so this is below the epidermis, there is a gland called the sebaceous gland.

在每根毛根旁边，在皮肤的真皮层内，在表皮下面，有一个腺体，称为皮脂腺。

And the sebaceous gland makes oily stuff, and the oily stuff is called sebum.

皮脂腺会产生油性物质，这种油性物质称为皮脂。

I know the name sort of evokes something kind of gross, but sebum is actually really cool and really important.

我知道这个名字有点恶心，但皮脂实际上非常酷而且非常重要。

The sebum gets injected, or seeps rather, into the area right around the hair as the hair starts to approach the surface, where it goes from essentially root to shaft.

当头发开始接近表面时，皮脂被注入或渗入头发周围的区域，从本质上讲，皮脂从根部延伸到发干。

And the sebum does two things.

皮脂有两个作用。

First of all, it forms a little bit of a seal right at the place where the hair exits the skin, and that seal is very important, actually, for waterproofing of your skin.

首先，它在头发离开皮肤的地方形成一点密封，实际上，这种密封对于皮肤的防水非常重要。

So we don't often think of ourselves as waterproof because we are so accustomed to water just landing on our skin and rolling off, but that's because of some of the oily properties of our skin.

因此，我们通常不认为自己是防水的，因为我们已经习惯了水落在我们的皮肤上并滚落，但这是因为我们皮肤的一些油性特性。

Now, it's also true that our skin is pretty densely packed with cells, but in the absence of sebum, we would not be as waterproof as we are.

现在，我们的皮肤确实充满了非常密集的细胞，但如果没有皮脂，我们就不会像现在这样防水。

Now, as I mentioned, sebum has two important properties.

现在，正如我所提到的，皮脂有两个重要的特性。

The other important property of sebum is that it actually is a strong antibacterial and antimicrobial.

皮脂的另一个重要特性是它实际上具有很强的抗菌和抗菌作用。

Most people don't realize this.

大多数人没有意识到这一点。

The oils of your skin provide a lot of immune boundary so that things don't get into the hair root or the region around it and infect our skin.

皮肤的油脂提供了很多免疫边界，这样东西就不会进入发根或其周围区域并感染我们的皮肤。

So sebum, while the name is sort of unattractive, to be honest, is actually performing some essential roles, both for waterproofing and for our immune system function, protecting us from various kinds of infection.

因此，皮脂虽然这个名字有点不吸引人，但说实话，它实际上发挥着一些重要的作用，既可以防水，也可以保护我们的免疫系统功能，保护我们免受各种感染。

We're going to return to sebum later As it turns out, sebum is also very important as it relates to psoriasis and as it relates to some of the fungal components that can cause hair loss.

稍后我们将回到皮脂 事实证明，皮脂也非常重要，因为它与牛皮癣有关，并且与一些可能导致脱发的真菌成分有关。

Okay, so just going to file that away.

好吧，所以就把它归档了。

There's another important component of the region around hairs, which is the arrector pili muscle.

毛发周围区域还有另一个重要组成部分，即立毛肌。

The arrector pili muscle is a muscle that lies diagonally between that bulb portion of the hair, or a little bit above it.

立毛肌是位于毛发球部之间对角线或略高于毛发球部的肌肉。

It goes up to the surface of the skin.

它上升到皮肤表面。

The arrector pili muscle is a muscle that contracts when we get cold or when we get scared.

立毛肌是一种当我们寒冷或害怕时收缩的肌肉。

So if you've ever had goosebumps, that's because the arrector pili muscle contracts, pulling the skin at the surface down around the little hair follicles, or at least where the hairs meet the surface of the skin.

因此，如果您曾经起过鸡皮疙瘩，那是因为立毛肌收缩，将小毛囊周围的表面皮肤向下拉，或者至少是在毛发与皮肤表面接触的地方。

And so those little bumps are actually where little micro-hairs reside, and the dimples between them are the dimples that occur when this arrector pili muscle pulls down.

所以这些小凸起实际上是小微毛所在的地方，它们之间的凹痕是当立毛肌向下拉时出现的凹痕。

Now, why would this muscle exist?

那么，为什么这块肌肉会存在呢？

It has a couple of important functions.

它有几个重要的功能。

One of the functions is that when it pulls down, it causes, as the name suggests, the hairs to stand up.

其功能之一是，顾名思义，当它向下拉时，会使毛发竖起来。

Maybe not perfectly vertical, but when you hear, "Oh, I was so frightened my hair stood up on end," that's because the hairs become erect.

也许不是完全垂直，但当你听到“哦，我吓坏了，我的头发竖起来了”，那是因为头发竖起来了。

They stand up.

他们站起来。

Now why would this happen when we get cold?

那么为什么当我们感冒时会发生这种情况呢？

It happens because when the hairs stand up, air can be trapped between those hairs and can actually warm our body.

发生这种情况是因为当毛发竖起时，空气会滞留在这些毛发之间，从而实际上可以温暖我们的身体。

This is not so much the case if you have very light hair on your skin.

如果你皮肤上的毛发很浅，情况就不是那么回事了。

If you're a very hairy person, this is going to be a more robust aspect of your physiology.

如果你是一个毛发非常多的人，这将是你生理机能的一个更强大的方面。

And yes, this is why dogs like Huskies can go out in the snow and still remain warm.

是的，这就是为什么像哈士奇这样的狗可以在雪地里出去并且仍然保持温暖。

When they get cold, their hairs actually stand up a bit on end because of the contraction of these arrector pili muscles, trapping air in there, and then their body warms the hair trapped beneath the hair, and it's sort of like they've got a blanket on made by the interface between the hair, the air, and their skin.

当他们变冷时，他们的头发实际上会因为立毛肌的收缩而竖立起来，将空气困在里面，然后他们的身体会温暖困在头发下面的头发，这有点像他们在头发、空气和皮肤之间的界面上盖了一条毯子。

So just to recap all the components of hair and the different things around it that are going to be relevant for understanding how to replace hair that's lost.

因此，我们回顾一下头发的所有组成部分以及头发周围的不同事物，这些内容将有助于了解如何替换丢失的头发。

We have the hair itself, which has the shaft that sticks out over the skin.

我们有头发本身，它的轴伸出皮肤。

It goes a little bit into the skin, but basically sticks out over the skin.

它有一点进入皮肤，但基本上伸出在皮肤上。

We have the root portion, which goes down into the skin.

我们有根部，它深入皮肤。

It goes through the epidermis and into the dermis.

它穿过表皮并进入真皮。

Then we have this bulb-like region down at the bottom.

然后我们在底部有一个类似灯泡的区域。

Down at the bottom of that bulb, we have stem cells that actually give rise to the actual hair, and we have pigmenting cells that pigment that hair.

在球茎的底部，我们有真正产生头发的干细胞，还有使头发着色的色素细胞。

In addition, and this is very important, there are capillaries that go into that bulb region down at the bottom of the hair, and that can serve and support the stem cells, the melanin-producing cells, which are called melanocytes.

此外，这一点非常重要，有毛细血管进入头发底部的球状区域，可以服务和支持干细胞，即产生黑色素的细胞，称为黑素细胞。

So the melanin-producing cells and the stem cells get a lot of blood flow that allows them to keep providing new hair, or the proteins that make up hair, and the pigment that goes into those hairs.

因此，产生黑色素的细胞和干细胞获得大量的血流，使它们能够不断提供新的头发，或构成头发的蛋白质，以及进入这些头发的色素。

And those little capillaries deliver not just nutrients and things of that sort, but they also deliver oxygen, because it turns out that the whole process of growing more hair is a very active process.

这些小毛细血管不仅提供营养物质和类似的东西，而且还提供氧气，因为事实证明，长出更多头发的整个过程是一个非常活跃的过程。

Now, as soon as you hear oxygen and you hear that the growth is an active process, that should cue you to why so many of the stories around how to keep your hair and regrow hair involve statements like, "Don't wear a hat, it'll make your hair fall out." Or, "If you want your hair to grow back, don't wear hats," or, "Massage your scalp," or, "Increase blood flow." Or why some people will suggest that people take peppermint oil, for instance, or menthol-type oils of different kinds and massage them into the scalp, things that make the scalp tingle.

现在，一旦您听到氧气并且听到生长是一个活跃的过程，这应该会提示您为什么这么多关于如何保持头发和头发再生的故事都涉及诸如“不要戴帽子，它会让您的头发脱落”之类的陈述。或者，“如果你想让头发重新长出来，就不要戴帽子”，或者“按摩头皮”，或者“增加血液流动”。或者为什么有些人会建议人们服用薄荷油，或者不同种类的薄荷醇类油，并将它们按摩到头皮上，这些东西会让头皮刺痛。

Or there will be light therapies designed to what?

或者会有光疗法设计用于什么目的？

To increase blood flow to the scalp.

以增加头皮的血液流动。

The whole rationale there is that you're trying to increase blood flow to the stem cell and the melanocyte populations that support the hairs and that actually create the hairs.

整个原理是，你试图增加流向干细胞和黑素细胞群的血流量，这些干细胞和黑素细胞群支持毛发并实际产生毛发。

Now whether or not those approaches work, we'll touch on a little bit later.

现在，无论这些方法是否有效，我们稍后都会讨论。

I'll just give you a little bit of a hint right now, which is that while no single one of those approaches that I described is known to regrow hair in a very robust way, because of the requirement for oxygen and nutrients, and because it's such an active process for the stem cells and melanocytes to grow and darken the hairs that grow out of your skin, it is true that manipulations or treatments that increase blood flow to those regions can at least slow the loss of hair, or can even extend the duration over which hairs continue to grow.

我现在就给你一点提示，虽然我所描述的这些方法中没有一种能够以非常稳健的方式重新长出头发，因为需要氧气和营养，而且因为干细胞和黑素细胞生长并使从皮肤上长出的毛发变黑是一个非常活跃的过程，但确实，增加流向这些区域的血流量的操作或治疗至少可以减缓毛发脱落，甚至可以延长毛发继续生长的时间成长。

So if you've heard things like, "Don't wear a hat if you want to maintain your hair," or, "Massage your scalp if you want your hair to grow faster," in some sense, that's true, but none of those manipulations on their own is going to robustly enhance the rate of your hair growth.

因此，如果您听说过这样的话：“如果您想保持头发，就不要戴帽子”，或者“如果您想让头发长得更快，就按摩头皮”，从某种意义上说，这是事实，但这些操作本身并不能显着提高头发的生长速度。

Those things are designed to be done in conjunction with some other treatments that have been shown in many, many clinical studies to increase the rate and duration of hair growth.

这些事情被设计为与许多其他治疗方法结合起来进行，这些治疗方法已在许多临床研究中显示，可以提高头发生长的速度和持续时间。

So now you have in mind a picture of what's happening at the level of individual hairs, and if you're anything like me, you're probably thinking, "Wow, there's a lot going on down there, just below the surface of the skin." And indeed there is.

所以现在你脑海中已经有了一幅关于单根毛发层面发生的事情的图片，如果你像我一样，你可能会想，“哇，就在皮肤表面下方，那里发生了很多事情。”确实有。

But really the things to think about are that stem cell population that actually give rise to the hair proteins, so that actually create the hair.

但真正需要考虑的事情是，干细胞群实际上产生了头发蛋白质，从而真正创造了头发。

The melanocytes that darken that hair, that give it pigment.

黑色素细胞使头发变黑，赋予头发色素。

That sebaceous gland and the oil sebum that provide some important antimicrobial and other properties to that general region.

皮脂腺和皮脂为该区域提供一些重要的抗菌和其他特性。

And that arrector pili muscle.

还有立毛肌。

That arrector pili muscle, as I mentioned earlier, is important for creating goosebumps, and it's important for keeping Huskies warm in cold environments.

正如我之前提到的，立毛肌对于产生鸡皮疙瘩很重要，对于哈士奇在寒冷的环境中保持温暖也很重要。

But it's doing some other really important things as well, and we'll talk about those as time goes on in this episode.

但它也做了一些其他非常重要的事情，我们将在本集中随着时间的推移讨论这些事情。

Right now, what I want to do is just talk for a moment about how hairs actually grow and why they grow the way they do.

现在，我想做的只是谈谈头发实际上是如何生长的以及它们为什么会这样生长。

This is extremely important toward understanding hair replacement and slowing hair loss.

这对于了解毛发替换和减缓脱发极其重要。

There are three basic phases of growth of a hair.

头发的生长分为三个基本阶段。

The first phase is the phase in which the stem cells down in that bulb give rise to the cells that make up the proteins of the hair.

第一阶段是球茎下方的干细胞产生构成头发蛋白质的细胞的阶段。

So the actual growth of the hair.

所以头发的实际生长。

And keep in mind that the hair is actually growing from the bottom up.

请记住，头发实际上是从下向上生长的。

Now, you might think, of course, it's growing from the bottom up.

现在，您可能会想，当然，它是自下而上增长的。

Everyone knows that.

每个人都知道这一点。

But a lot of people think that the hair starts growing right at the surface of the skin.

但很多人认为毛发是从皮肤表面开始生长的。

That's not the way it works.

这不是它的工作方式。

The hair is actually growing from deep within the root and stacking up, and then eventually extends out across the top of the skin.

毛发实际上是从根部深处生长并堆积起来，然后最终延伸到皮肤顶部。

That growth phase is called the anagen phase, A-N-A-G-E-N.

该生长阶段称为毛发生长初期阶段，A-N-A-G-E-N。

And this, for some people, will ring a bell because if you've ever been interested in weightlifting or even if you're an endurance runner, you'll hear about things that are anabolic, that promote growth, so ana-, of growth, or catabolic, that promote breakdown.

对于某些人来说，这会敲响警钟，因为如果你曾经对举重感兴趣，或者即使你是一名耐力跑者，你也会听到合成代谢的东西，促进生长，所以合成代谢，生长或分解代谢，促进分解。

So the first phase of hair growth is called the anagen phase, and it's a period of varying duration depending on which hair in the body we're talking about.

因此，毛发生长的第一阶段称为生长期，该阶段的持续时间各不相同，具体取决于我们所讨论的是体内的毛发。

So the anagen, or the growth phase, for hairs on the head, as I mentioned earlier, is anywhere from two to eight years.

因此，正如我之前提到的，头发的生长期或生长期为两到八年。

For most people, it's going to be about six years.

对于大多数人来说，这大约是六年。

What this means is that if we were to just not cut our hair, just let our hair grow for two to eight years, that hair would eventually grow to a length that it was at its maximum and then would stop growing.

这意味着，如果我们不剪头发，只是让头发生长两到八年，头发最终会长到最大长度，然后停止生长。

So we can say that the anagen phase of hairs on the scalp is two to eight years.

所以我们可以说头皮上的毛发的生长期是二到八年。

The duration of the growth phase.

生长期的持续时间。

Contrast that, for instance, with the duration of the anagen phase for hairs of the eyebrows.

例如，与眉毛毛发生长初期的持续时间进行对比。

The hairs of the eyebrows grow about 4.2 millimeters per month.

眉毛每月大约生长 4.2 毫米。

Believe it or not, people have measured this sort of thing.

不管你信不信，人们已经测量过这种事情。

Now, that's an average, so some people are going to have eyebrows that grow much longer per month.

现在，这是平均值，所以有些人的眉毛每月会长得更长。

I'm somebody who, for instance, has mostly the same length eyebrow hairs, but every once in a while, I get one of those eyebrow hairs that really seems to be heading off my head.

例如，我是一个眉毛长度基本相同的人，但每隔一段时间，我就会发现一根眉毛似乎真的从我的头上脱落了。

It really wants out of there.

它真的想离开那里。

And so it's much longer than the rest.

所以它比其他的要长得多。

What does that mean?

这意味着什么？

Does it mean that it grew faster?

这是否意味着它增长得更快？

Maybe, but chances are the stem cell population in that particular eyebrow follicle for that one eyebrow hair is longer than it is for the others.

也许吧，但很可能特定眉毛毛囊中的干细胞群会导致一根眉毛比其他眉毛长。

This is really important.

这真的很重要。

I'm trying to illustrate two principles at once here.

我试图在这里同时说明两个原则。

The first principle is that different hairs on your body, including the hairs on your scalp, have a growth phase of different duration.

第一个原则是，身体上的不同毛发，包括头皮上的毛发，有不同持续时间的生长期。

This is why the hairs on your head can grow very, very long because they have a very long anagen or growth phase, and the hairs on your eyebrows will only grow for a few months before they actually fall out and then have to undergo replication of the stem cells to give you new eyebrow hair to then grow.

这就是为什么你头上的毛发可以长得很长，因为它们有一个很长的生长期或生长期，而眉毛上的毛发只会生长几个月，然后就会真正脱落，然后必须经过干细胞的复制，让你长出新的眉毛。

What's important here is not just that there are differences in the duration of the growth phase, but rather that the rate of hair growth is not something that tends to differ within a given body region.

这里重要的不仅是生长期的持续时间存在差异，而且在特定的身体区域内，毛发的生长速度也不会有所不同。

You'll hear people say, "Oh, my hair grows really, really fast." Other people will say, "Oh, my hair grows really, really slowly."

你会听到人们说：“哦，我的头发长得非常非常快。”其他人会说：“哦，我的头发长得非常非常慢。”

That is probably not the case.

情况可能并非如此。

While there could be slight differences in the rate of growth, that is the addition of more keratin to the actual hairs, so creation of more hair more quickly, almost certainly what's happening is that the duration of the anagen phase in some people is just much longer than it is in other people.

虽然生长速度可能略有不同，即在实际毛发中添加了更多角蛋白，因此更快地产生更多毛发，但几乎可以肯定的是，某些人的毛发生长初期阶段的持续时间比其他人长得多。

And we don't realize this, and we tend to think more in terms of how fast hair grows, because if you were to just look at somebody's hair, you'd say, "Oh, they're all more or less the same length." I mean, some people's bangs are shorter than the back because they cut them.

我们没有意识到这一点，我们倾向于更多地考虑头发生长的速度，因为如果你只看某人的头发，你会说，“哦，他们的长度都或多或少相同。”我的意思是，有些人的刘海比后面短，因为他们剪了刘海。

But if they were to just grow their hair, you'd say, "Oh, it's all more or less the same length." But if we were to zoom in with a microscope, we would see that there are a lot of hairs down there in between the other hairs that are very, very short or even tiny, tiny, tiny.

但如果他们只是留头发，你会说，“哦，头发的长度或多或少都一样。”但如果我们用显微镜放大，我们会看到在其他毛发之间有很多毛发，这些毛发非常非常短，甚至很小很小。

And those are coming in as the other ones are finishing their anagen phase.

当其他人完成生长期时，这些人就会进来。

Okay?

好的？

So that's the anagen or growth phase.

这就是生长期或生长期。

After the anagen phase comes the catagen phase.

毛发生长初期阶段之后是毛发生长中期阶段。

Again, this resembles the word catabolic or the breakdown phase.

同样，这类似于分解代谢或分解阶段这个词。

During the catagen phase, the hair is actually receding not from the top down to the skin surface and then into the root, but the other way.

在退行期，毛发实际上并不是从上往下退到皮肤表面，然后进入根部，而是相反。

It's actually receding from that bulb region up toward the surface.

它实际上是从灯泡区域向上退向表面。

And that catagen phase is going to also be of different duration depending on which area of the body you're in, and it will vary a little bit depending on who you are, meaning from person to person.

根据您所处的身体部位，该退行期的持续时间也将有所不同，并且根据您是谁（即因人而异），它也会略有不同。

We'll talk about the influences on the anagen and catagen phase in a moment.

我们稍后将讨论对毛发生长初期和毛发生长中期阶段的影响。

Why is it important that it actually recedes from the inside out?

为什么它实际上从内向外退缩很重要？

Well, that's important because as it does that, there's actually a change in that bulb region down below, because normally there's an interface, there's a conversation that's occurring between the stem cell population, the melanocytes, and the hair itself, and they support each other.

嗯，这很重要，因为这样做时，下面的球茎区域实际上发生了变化，因为通常有一个界面，干细胞群、黑素细胞和头发本身之间正在发生对话，并且它们相互支持。

And remember, there's blood vessels going into that area, or rather capillaries that are feeding that area as well.

请记住，有血管进入该区域，或者更确切地说，毛细血管也在为该区域供血。

After the catagen phase comes the telogen phase, which means rest.

退行期之后是休止期，这意味着休息。

The telogen phase is a period in which no new hair proteins are being added by those stem cells.

休止期是这些干细胞不添加新的毛发蛋白质的时期。

And during that telogen phase, that bulb down there at the bottom, instead of being nice and oval and really having a lot of space in it with all these different things like stem cells, starts to pinch off from the little tube that comes down from the surface of the skin that normally would have a hair in it.

在休止期，底部的那个球状体不再是漂亮的椭圆形，里面有很多空间容纳所有这些不同的东西，比如干细胞，而是开始从皮肤表面下来的小管子上掐断，通常会有一根头发。

It starts to pinch off, and at some point, many hair follicles pinch off that bulb region and it recedes and dies.

它开始被夹断，在某个时刻，许多毛囊夹断了球根区域，然后它就退缩并死亡。

And when it recedes and dies, the stem cell population and the melanocytes go with it.

当它消退并死亡时，干细胞群和黑素细胞也随之消失。

In other words, there is no longer a population of stem cells to give rise to more hair after that telogen phase.

换句话说，在休止期之后，不再有干细胞群产生更多的毛发。

And there's no longer melanocytes to pigment the hair, and in fact, the hair isn't there anymore, so there's no hair even to pigment after that telogen phase, unless It's a hair of a particular type, such as the hair on your scalp, which can then re-enter the cell cycle and get back into an anagen phase and regrow more hair from stem cells.

并且不再有黑色素细胞使头发着色，事实上，头发已经不存在了，所以在休止期之后甚至没有头发可以着色，除非它是特定类型的头发，例如头皮上的头发，然后它可以重新进入细胞周期并回到生长期并从干细胞重新长出更多的头发。

Okay, so there are three critical stages of the life cycle of a hair that are relevant to today's conversation.

好的，头发生命周期的三个关键阶段与今天的讨论相关。

There's the anagen phase, during which the hair grows.

毛发生长初期是毛发生长初期。

There's the catagen phase, during which the hair actually starts to recede and die.

有一个退行期，在此期间头发实际上开始脱落并死亡。

The protein's actually disappearing from the bottom up.

蛋白质实际上是自下而上消失的。

And then we have the telogen phase, which is the phase in which the stem cell population is what's called semi-quiescent, semi-quiet, or completely quiescent, where it's not active at all.

然后是休止期，在这个阶段干细胞群处于所谓的半静止、半静止或完全静止状态，在这个阶段它根本不活跃。

Those three phases make up the life cycle of a hair.

这三个阶段构成了头发的生命周期。

Keeping in mind that for some hairs, they can re-enter the life cycle and go back into the anagen phase if there's stem cells there, and if there is oxygen there, and if there is sufficient blood support, and, and this is very important, and if there are the appropriate hormonal signals to support growth, and there is a reduction or an absence in the hormone signals that actually trigger that telogen phase.

请记住，对于某些毛发来说，如果那里有干细胞，如果那里有氧气，如果有足够的血液支持，并且这非常重要，如果有适当的激素信号来支持生长，并且实际上触发休止期的激素信号减少或缺失，它们可以重新进入生命周期并回到毛发生长初期阶段。

I make this point now because much of the rest of today's discussion is going to focus on why particular hormones, such as dihydrotestosterone, cause hair loss, and why inhibiting things like dihydrotestosterone can support the preservation of hair that you have and the regrowth of hair.

我现在提出这一点是因为今天讨论的其余部分将集中在为什么特定激素（例如二氢睾酮）会导致脱发，以及为什么抑制二氢睾酮等物质可以支持头发的保存和头发的再生。

And to make a long story very short, and then we'll get into some additional details that are relevant and that I hope you'll stick around to listen to, dihydrotestosterone, which is a derivative of testosterone, causes changes in that bulb region where the stem cells reside.

长话短说，然后我们将讨论一些相关的附加细节，我希望您能留下来听听，二氢睾酮是睾酮的衍生物，会导致干细胞所在的球部区域发生变化。

It shortens or halts the anagen phase of hair growth, and it extends and promotes the catagen and telogen phase.

它缩短或停止头发生长的生长期，并延长和促进毛发生长的生长期和休止期。

So when we hear that, oh, dihydrotestosterone makes your hair fall out, or estrogen makes your hair grow, there are real chemical, or we should say biochemical, legitimate reasons as to why that is, but it all comes back to these three phases of hair growth, the anagen growth phase, the catagen catabolic or hair loss phase, and the telogen phase, which is a rest period in which the hairs can either come back if it reenters the anagen phase, or maybe it's over for good.

因此，当我们听到，哦，二氢睾酮使你的头发脱落，或雌激素使你的头发生长时，确实有化学的，或者我们应该说生化的，合理的理由来解释为什么会这样，但这一切都回到了头发生长的三个阶段，毛发生长初期生长阶段，毛发生长中期分解代谢或脱发阶段，以及毛发生长终期阶段，这是一个休息期，如果毛发重新进入毛发生长初期阶段，毛发可以回来，或者也许一切都结束了。

Hormones are the accelerator and the brake on each one of those phases.

激素是每个阶段的加速器和制动器。

There is so much NFL on ESPN right now.

ESPN 上现在有很多 NFL 节目。

Monday Night Football, plus pre-game and post-game.

周一橄榄球之夜，以及赛前和赛后。

NFL Live, NFL Prime Time.

NFL 直播，NFL 黄金时间。

Everything you need to stay on top of every game, every week.

每周掌握每场比赛所需的一切。

Unbelievable.

难以置信。

And now NFL Network is on the ESPN app.

现在 NFL Network 已登陆 ESPN 应用程序。

More football, more coverage, more ways to watch.

更多足球比赛、更多报道、更多观看方式。

Football's on all season long on ESPN and streaming on the ESPN app.

ESPN 提供整个赛季的足球赛事直播，并通过 ESPN 应用程序进行直播。

So now you have in mind the anatomy of the hair and the area from which it grows and the stem cells, et cetera.

现在您已经了解了头发的解剖结构、头发生长的区域以及干细胞等。

The fact that there's capillary innervation delivering oxygen and blood flow to the stem cells that give rise to the hair, and that there are these three critical phases of hair growth, anagen, catagen, and telogen.

事实上，毛细血管神经支配将氧气和血流输送到产生头发的干细胞，并且头发生长存在三个关键阶段：毛发生长初期、毛发生长中期和毛发生长终期。

Now let's talk about the accelerators on hair growth and the brakes on hair growth.

现在让我们谈谈头发生长的加速器和头发生长的刹车。

There are many accelerators on hair growth, but the first one that I really want to underscore is blood flow itself, which equates to the delivery of nutrients and oxygen.

头发生长的促进剂有很多，但我真正想强调的第一个是血液流动本身，它相当于营养物质和氧气的输送。

This is very important, and it explains a lot of the treatments for halting and reversing hair loss.

这非常重要，它解释了许多阻止和逆转脱发的治疗方法。

For instance, one of the longest-standing treatments for halting and reversing hair loss is so-called minoxidil.

例如，用于阻止和逆转脱发的最古老的治疗方法之一是所谓的米诺地尔。

Minoxidil, sometimes also referred to by the brand name Rogaine, was actually a drug that was developed to treat hypertension.

米诺地尔，有时也被称为落健（Rogaine），实际上是一种用于治疗高血压的药物。

So this is a cardiac drug that lowers blood pressure, and it does that by causing vasodilation.

这是一种降低血压的心脏药物，它通过引起血管舒张来实现这一点。

It allows more blood flow, not just to the hairs on your scalp, but to hairs everywhere on your body.

它可以让更多的血液流动，不仅流向头皮上的毛发，还流向身体各处的毛发。

And indeed, most people don't realize this, but minoxidil won't just slow the loss of hair from your scalp, it is also effective at slowing the loss of hair elsewhere in your body.

事实上，大多数人都没有意识到这一点，但米诺地尔不仅能减缓头皮脱发，还能有效减缓身体其他部位的脱发。

How does it do that?

它是如何做到的？

Well, you now know one of the major ways it does that.

好吧，您现在知道了它实现这一目标的主要方法之一。

It does that by extending the anagen phase.

它通过延长毛发生长初期阶段来实现这一点。

So it basically makes that phase a bit longer.

所以它基本上使这个阶段变得更长一些。

It doesn't make it much, much longer, which is why for most people who are losing their hair quickly or who have already lost their hair, minoxidil alone is not going to be a sufficient treatment.

它不会使头发变得太长，这就是为什么对于大多数快速脱发或已经脱发的人来说，仅使用米诺地尔不足以治疗。

However, minoxidil has been shown to be effective at slowing rates of hair loss in people that are starting to experience some hair loss.

然而，米诺地尔已被证明可以有效减缓开始出现脱发的人们的脱发速度。

I'll get into dosages and things of that sort a little bit later.

稍后我会讨论剂量和类似的事情。

But right now, I just want to really focus on the logic of why people would take this drug, which is lowering hypertension, at all, as it relates to hair loss, right?

但现在，我只想真正关注为什么人们会服用这种药物的逻辑，这种药物根本可以降低高血压，因为它与脱发有关，对吗？

That might seem kind of crazy until you understand the anatomy and the growth of hairs, which you now do.

在您了解毛发的解剖结构和生长之前，这可能看起来有点疯狂，而您现在已经了解了。

So that's what minoxidil is doing.

这就是米诺地尔正在做的事情。

It's creating more blood flow to the hairs, which, because minoxidil does have this positive effect, at least most people would like to slow their rates of hair loss on their scalp anyway, it tells you that blood flow and delivery of oxygen and other nutrients from the blood is pretty critical, if not very critical, for the support of the hair growth cycle itself.

它创造了更多流向头发的血液，因为米诺地尔确实有这种积极作用，至少大多数人都希望减缓头皮脱发的速度，它告诉你，血液流动以及血液中氧气和其他营养物质的输送对于支持头发生长周期本身来说是非常重要的，如果不是非常重要的话。

Now, again, we haven't talked at all about the sorts of chemicals or the signals within the body, such as hormones, that actually direct the growth of hairs.

现在，我们再次讨论了体内实际上指导毛发生长的化学物质或信号的种类，例如激素。

Here, we're just talking about a mechanical change.

在这里，我们只是谈论机械变化。

Allow more blood flow to the region and thereby extend the anagen phase, which is exactly what happens with minoxidil.

让更多的血液流向该区域，从而延长生长期，这正是米诺地尔所发生的情况。

Now, minoxidil does have other effects, and this is why dosing of minoxidil becomes a little bit complicated and can be a little bit tricky to troubleshoot It can greatly lower blood pressure or lower blood pressure just a little bit, depending on how sensitive somebody is to that particular drug.

现在，米诺地尔确实还有其他作用，这就是为什么米诺地尔的剂量变得有点复杂，而且解决起来也有点棘手。它可以大大降低血压，也可以稍微降低一点血压，具体取决于人们对该特定药物的敏感程度。

So oftentimes, physicians will start people on minoxidil dosages that are very low, ideally that would be the case, and then ratchet it up in order to figure out where the minimal effective dose or the kind of critical threshold is, beyond which they start experiencing some pretty uncomfortable side effects, such as swelling of the ankles or headaches or dizziness.

通常情况下，医生会开始给人们服用非常低的米诺地尔剂量，理想情况下就是这样，然后逐渐增加剂量，以确定最小有效剂量或临界阈值，超过这个剂量，他们就会开始出现一些非常不舒服的副作用，例如脚踝肿胀或头痛或头晕。

These things can happen with the use of Rogaine, AKA minoxidil.

使用落建（又名米诺地尔）可能会发生这些情况。

Now, minoxidil has also been associated with increases in the hormone prolactin.

现在，米诺地尔还与催乳素激素的增加有关。

Prolactin is a hormone that's released from the pituitary.

催乳素是一种从垂体释放的激素。

It is a hormone that acts also as a bit of a neurotransmitter, like many hormones, and it tends to be antagonistic or in opposite to dopamine.

与许多激素一样，它也是一种神经递质，并且往往与多巴胺具有拮抗作用或相反作用。

So dopamine is a neurochemical.

所以多巴胺是一种神经化学物质。

It's actually a neuromodulator, meaning it modulates the activity of a bunch of neural circuits in the brain.

它实际上是一种神经调节剂，这意味着它可以调节大脑中一堆神经回路的活动。

It also controls the release of various hormones in the body.

它还控制体内各种激素的释放。

Dopamine is almost always associated with states of motivation, pursuit, and drive.

多巴胺几乎总是与动机、追求和驱动力的状态联系在一起。

It has a little bit of a kind of feel-good element to it, which is why a lot of people think dopamine is associated with reward and pleasure, but it's really about energy, motivation, and drive.

它有一点让人感觉良好的元素，这就是为什么很多人认为多巴胺与奖励和快乐有关，但它实际上与能量、动力和动力有关。

Dopamine and prolactin are, as I mentioned before, antagonistic to one another.

正如我之前提到的，多巴胺和催乳素是相互拮抗的。

They're in sort of a push-pull.

它们处于某种推拉状态。

So people who take minoxidil, especially if they're very sensitive to it or they take dosages that are too high, will experience increases in prolactin that, in turn, can cause things like reductions in libido, reductions in overall feelings of wellbeing, apathy, and in some cases where the elevations in prolactin are more extreme, they can experience, for instance, increase in male breast tissue, gynecomastia, or even small bits of milk letdown, things of that sort.

因此，服用米诺地尔的人，尤其是对米诺地尔非常敏感或服用剂量过高的人，会出现催乳素升高，进而导致性欲降低、整体幸福感降低、冷漠等，在某些催乳素升高更为极端的情况下，他们可能会出现男性乳腺组织增加、男性乳房发育症，甚至少量乳汁分泌等类似情况。

In women who take minoxidil, the side effects are much like the ones experienced in men.

对于服用米诺地尔的女性来说，其副作用与男性所经历的副作用非常相似。

So there can be swelling, edema of the tissues, because if you get too much vasodilation and too much lowering of blood pressure, that's not good.

因此，组织可能会肿胀、水肿，因为如果血管舒张过多、血压降低过多，那就不好了。

Headaches, dizziness, and so on.

头痛、头晕等。

So dosing of minoxidil is really important.

所以米诺地尔的剂量非常重要。

If somebody's going to use minoxidil in order to try and slow or reverse hair loss, and again, it mainly is going to be used to slow rates of hair loss, not to actually reverse hair loss, the really key thing is to get that dosage right.

如果有人要使用米诺地尔来尝试减缓或逆转脱发，那么它主要是用来减缓脱发速度，而不是真正逆转脱发，真正关键的是剂量正确。

So the ranges of minoxidil that you'll see suggested and that people use out there are vast.

因此，您会看到建议的和人们使用的米诺地尔的范围很广。

And I should also mention that there are two major routes by which people get minoxidil to the hair follicle.

我还应该提到，人们将米诺地尔输送到毛囊有两种主要途径。

One is to take it systemically as a pill, where it goes into the general circulation.

一种是将其作为药丸全身服用，进入全身循环。

The other is to take it topically as a cream.

另一种是将其作为霜剂局部服用。

There are prescription and non-prescription forms of minoxidil, just to further complicate things.

米诺地尔有处方和非处方两种形式，只是让事情变得更加复杂。

But the ranges of oral minoxidil that you'll see out there and that people take range anywhere from 0.25 milligrams all the way up to 5 milligrams per day.

但您会看到人们服用的口服米诺地尔的范围从每天 0.25 毫克一直到 5 毫克不等。

So that's an enormous range.

所以这是一个巨大的范围。

That's like a 20-fold range.

这就像 20 倍的范围。

The topical minoxidil is also found in various concentrations.

外用米诺地尔也有不同浓度。

The typical concentration is going to be a 5% concentration that people will use once per day.

典型浓度为 5%，人们每天使用一次。

Topical treatment with minoxidil at 5% concentration is thought to just stay at the scalp, but we now know that it can go systemically.

5%浓度的米诺地尔局部治疗被认为只能停留在头皮上，但我们现在知道它可以全身治疗。

It can get into the general bloodstream.

它可以进入全身血液。

Why that is should make complete sense to you, because when you put something on your scalp, I've already told you these little pits, these little tubes that go down to those bulb regions below the skin that have direct access to the blood supply.

为什么这是你应该完全理解的，因为当你在头皮上放一些东西时，我已经告诉过你这些小坑，这些小管，这些小管通向皮肤下方的球状区域，可以直接进入血液供应。

So when you massage something into your scalp, it not only has the opportunity to get into your general circulation, it often does, especially if it's something that's very water-soluble and that way can get into the capillaries and into the general bloodstream.

因此，当您将某些东西按摩到头皮上时，它不仅有机会进入您的全身循环，而且经常如此，特别是如果它是水溶性很强的东西，这样可以进入毛细血管并进入全身血液。

Although topical treatments, of which we're going to discuss a number of them today, don't tend to get into the general circulation as robustly as taking something by way of pill or capsule.

尽管局部治疗（我们今天将讨论其中的一些）往往不如通过药丸或胶囊服用某些药物那样有效地进入全身循环。

Okay, so minoxidil works by way of increasing blood flow to the stem cell niche below the hair.

好的，米诺地尔的作用是增加头发下方干细胞生态位的血流量。

The dosage ranges of the oral minoxidil are tremendous, .25 milligrams all the way up to 5 milligrams once per day.

口服米诺地尔的剂量范围很大，每天一次从 0.25 毫克一直到 5 毫克。

The dosage range of the topical solutions tends to be a little bit more confined.

局部溶液的剂量范围往往受到一些限制。

Typically, it's a 5% solution, and it's recommended that people use it one time daily, maybe twice daily.

通常，它是 5% 的溶液，建议人们每天使用一次，也许每天两次。

It's also important, by the way, if you're going to take this route, that you actually leave that solution on the scalp for three to five minutes.

顺便说一句，如果您打算采取这种方法，那么将溶液留在头皮上三到五分钟也很重要。

This is important and should make complete sense as to why it's important.

这很重要，并且应该完全理解为什么它很重要。

You can't just rub the stuff into your head and then rinse it off and expect it to be absorbed.

你不能只是把这些东西擦到头上，然后冲洗掉，然后指望它被吸收。

It actually needs to seep down into those hair follicles and access the niche.

它实际上需要渗入毛囊并进入利基。

How do people arrive at the correct dosage for minoxidil?

人们如何获得米诺地尔的正确剂量？

Well, for better or for worse, really, in some cases, it's accomplished by finding out that you have an unwanted side effect, like dizziness or swelling of your ankles or edema or, I would hope this wouldn't be the case, but something that suggests there's hyperprolactinemia.

好吧，无论好坏，实际上，在某些情况下，这是通过发现您有不需要的副作用来完成的，例如头晕或脚踝肿胀或水肿，或者，我希望情况不会是这样，但表明存在高催乳素血症。

You could get a blood test to measure your prolactin, or you perhaps notice a drop in libido or some lethargy, these sorts of things that are common to reduced levels of dopamine, increased levels of prolactin.

您可以进行血液检查来测量催乳素，或者您可能会注意到性欲下降或有些嗜睡，这些都是多巴胺水平降低、催乳素水平升高的常见现象。

I would hope that if people are working with a physician or if they're not, in taking minoxidil, that they would start with the lowest possible dose.

我希望，无论人们是否与医生合作，在服用米诺地尔时，都应从尽可能低的剂量开始。

So for oral minoxidil, that would be .25 milligrams, and then increase it as needed rather than jumping in right at 5 milligrams.

因此，对于口服米诺地尔来说，剂量为 0.25 毫克，然后根据需要增加剂量，而不是立即增加到 5 毫克。

Because some of those side effects, in particular the fluid retention and the hyperprolactinemia, can be pretty uncomfortable and can disrupt a lot of aspects of life that most all of us consider desirable.

因为其中一些副作用，特别是液体潴留和高催乳素血症，可能会非常不舒服，并且可能会扰乱我们大多数人认为理想的生活的许多方面。

Okay, so we're really focusing right now on treatments that relate to the critical requirement for hair stem cells to receive blood flow in order to receive oxygen and nutrients to get the hair to grow.

好的，所以我们现在真正关注的是与毛发干细胞接收血流的关键要求相关的治疗，以便接收氧气和营养，使毛发生长。

And that's really what minoxidil is about.

这就是米诺地尔的真正意义所在。

It's also what all of those anecdotes you hear are all about, like massaging the scalp or putting red light on the scalp.

这也是您听到的所有轶事的全部内容，例如按摩头皮或在头皮上照射红光。

Although red light might do some other things, in general, heating or lighting of the scalp or massaging of the scalp is really designed to increase blood flow to the scalp.

尽管红光可能还有其他一些作用，但一般来说，加热或照明头皮或按摩头皮实际上是为了增加流向头皮的血液。

Now, the reason minoxidil works at all is because it is going to increase blood flow around the clock, and that's because people are taking it topically and it's seeping into the general circulation, or at least it stays somewhat restricted to the hair cell niche, or they're taking it orally and it makes it to that hair cell niche below the follicle.

现在，米诺地尔之所以起作用，是因为它会全天候增加血流量，这是因为人们局部服用它，它会渗透到全身循环中，或者至少它在一定程度上限制在毛细胞生态位中，或者他们口服它，它会进入毛囊下方的毛细胞生态位。

When we massage our scalp, however, that's a transient thing.

然而，当我们按摩头皮时，这只是暂时的事情。

I can massage my scalp right now.

我现在可以按摩头皮。

I'm no doubt increasing blood flow to certain areas.

毫无疑问，我会增加某些区域的血流量。

I'm probably decreasing blood flow to the areas I'm pushing down on.

我可能正在减少流向我按压区域的血流量。

But it's all temporary.

但这都是暂时的。

I don't know many people that can massage their scalp enough during the day, or long enough during the day rather, that it would sufficiently increase blood flow.

我不知道有多少人能够在白天充分按摩头皮，或者在白天按摩足够长的时间，从而充分增加血液流动。

With that said, it is clear that increasing blood flow to the scalp by way of reducing hypertension, which is effectively accomplished by broadening, by expanding the blood vessels and capillaries, is an effective way to at least hold on to the hair that you have.

话虽如此，很明显，通过降低高血压来增加头皮的血流量（通过扩张血管和毛细血管来有效地实现这一点）是至少保持头发的有效方法。

Is it going to completely halt hair loss if you have a strong genetic bias towards hair loss?

如果您对脱发有强烈的遗传偏见，它会完全阻止脱发吗？

No. Is it going to reverse hair loss?

不会。它能逆转脱发吗？

Very unlikely that it will.

可能性极小。

But it can slow hair loss or even maintain the hair that you have.

但它可以减缓脱发，甚至可以保持现有的头发。

So if we were to take a step back and ask ourselves what other sorts of drug treatments are out there besides minoxidil that increase blood flow and that might increase the rates of hair growth, or more likely, increase maintenance of hair that one already has by increasing blood flow to the niche.

因此，如果我们退后一步，问问自己，除了米诺地尔之外，还有哪些其他药物治疗可以增加血流量，并可能提高头发的生长速度，或者更有可能的是，通过增加流向生态位的血流量来增强对已有头发的维护。

And nowadays, there are more and more doctors who are familiar with this requirement for blood flow, understand the mechanisms by which minoxidil works, and understand the vast desire out there for people to hold on to the hair they have and regrow hair, and they're prescribing things like low-dose tadalafil, so 2.5 milligram to five-milligram tadalafil.

如今，越来越多的医生熟悉这种血液流动的要求，了解米诺地尔的工作机制，了解人们对保留头发并使头发再生的巨大渴望，他们开出低剂量他达拉非之类的药物，即 2.5 毫克到 5 毫克他达拉非。

Tadalafil was initially discovered as a drug to treat prostate health.

他达拉非最初被发现是一种治疗前列腺健康的药物。

It was a drug that we now know can increase blood flow to the prostate and thereby offset some of the issues associated with an aging prostate.

我们现在知道这种药物可以增加前列腺的血流量，从而抵消与前列腺老化相关的一些问题。

Higher doses of tadalafil, sometimes also referred to by its brand name, which is Cialis, are used to treat erectile dysfunction, but at the dosages that are used to increase blood flow to the prostate, and that now a number of doctors are using to increase blood flow, not just to the prostate, but to all regions of the body, including the scalp, such as 2.5 to five milligrams tadalafil.

高剂量的他达拉非（有时也称为西力士）用于治疗勃起功能障碍，但其剂量用于增加前列腺的血流量，现在许多医生正在使用该剂量来增加血流量，不仅是前列腺的血流量，而且是身体所有区域（包括头皮）的血流量，例如 2.5 至 5 毫克他达拉非。

So this is something that I think deserves attention because it falls under the umbrella of increasing blood flow to the hair stem cell niche in order to maintain hair.

所以我认为这是值得关注的事情，因为它属于增加流向毛发干细胞生态位的血液以维持头发的保护伞。

It is not something that most doctors are going to be familiar with as the way to reverse hair loss, because it won't do that.

大多数医生都不熟悉这种方法来逆转脱发，因为它起不了作用。

But the use of low-dose tadalafil to slow rates of hair loss is very much, in a logical mechanistic sense, exactly the same as the logic of using minoxidil to slow rates of hair loss.

但从逻辑机制的角度来看，使用低剂量他达拉非来减缓脱发速度与使用米诺地尔来减缓脱发速度的逻辑完全相同。

It's all about increasing blood flow to support the stem cell niche below the hair follicle.

这一切都是为了增加血流量以支持毛囊下方的干细胞生态位。

The critical requirement for blood flow, oxygen, and nutrients to the stem cell niche is also why you hear a lot nowadays about the use of PRP, platelet-rich plasma, for trying to offset hair loss or even reverse hair loss.

干细胞生态位对血流、氧气和营养物质的关键要求也是为什么您现在听到很多关于使用 PRP（富含血小板的血浆）来试图抵消脱发甚至逆转脱发的原因。

We're going to do an entire episode about PRP.

我们将制作一整集关于 PRP 的节目。

It is pretty controversial in certain circles and well accepted in other circles.

它在某些圈子里颇具争议，但在其他圈子里却广为接受。

A couple of key things to understand about PRP.

关于 PRP 需要了解的几个关键事项。

First of all, it is being used in multiple tissues for different purposes in different clinics.

首先，它在不同的诊所用于不同目的的多种组织。

So for instance, board-certified physicians in the United States, Canada, and Europe are doing PRP injections into ovaries to try and expand the number of healthy follicles and eggs so that people can conceive later in life, or even earlier in life if they don't have many follicles.

例如，美国、加拿大和欧洲的委员会认证医生正在向卵巢进行 PRP 注射，以尝试增加健康卵泡和卵子的数量，以便人们可以在晚年受孕，如果卵泡不多，甚至可以更早受孕。

People are getting PRP injections into their joints in order to try and support joint health.

人们正在关节中注射 PRP，以尝试支持关节健康。

People are getting PRP injections into just about every tissue you can think of.

人们几乎将 PRP 注射到您能想到的所有组织中。

However, PRP, despite what you may have heard, is not stem cells.

然而，尽管您可能听说过，PRP 并不是干细胞。

Somebody tells you they're injecting stem cells, they're either outside the US, Canada, or Northern Europe, or they're injecting something else.

有人告诉你他们正在注射干细胞，他们要么在美国、加拿大或北欧境外，要么正在注射其他东西。

So you want to really look into that.

所以你想真正调查一下。

The safety issues there are the subject totally deserving of an entire episode.

那里的安全问题完全值得用整集来讨论。

I'm not necessarily opposed to the future of stem cells as a treatment, but keep in mind that stem cells are cells that can give rise to lots of other cell types, and they are cells that divide and replicate.

我不一定反对干细胞作为一种治疗方法的未来，但请记住，干细胞是可以产生许多其他细胞类型的细胞，并且它们是分裂和复制的细胞。

And there's a name for that when it happens in the adult body when you don't want that, and that's called cancer.

当你不希望这种情况发生在成人体内时，有一个名字，那就是癌症。

Tumors are overproduction of cells from stem cells when those stem cells ordinarily should be quiescent.

肿瘤是干细胞过度产生的细胞，而这些干细胞通常应该是静止的。

Okay?

好的？

So keep in mind the difference between stem cells and PRP.

因此请记住干细胞和 PRP 之间的区别。

PRP, platelet-rich plasma, again, is legal in the US and many other places because it involves drawing somebody's blood, spinning it down at a particular speed, which separates out different components within the blood, then taking the platelets and re-injecting those in a solution back into the person's body.

PRP（富含血小板的血浆）在美国和许多其他地方也是合法的，因为它涉及抽取某人的血液，以特定的速度将其旋转，从而分离出血液中的不同成分，然后取出血小板并将其重新注射回人体内。

So platelet-rich plasma or PRP is platelet-enriched plasma from that person.

因此，富含血小板的血浆或 PRP 是来自该人的富含血小板的血浆。

But the basis of PRP is really to encourage nutrient delivery to a particular region in the body using somebody's own platelets, because those platelets are enriched for various nutrients.

但 PRP 的基础实际上是鼓励使用某人自己的血小板将营养物质输送到体内的特定区域，因为这些血小板富含各种营养物质。

So people are getting PRP injections into their scalp.

因此，人们开始在头皮上注射 PRP。

Those are not stem cell injections, those are PRP injections into the scalp, with some moderate success.

这些不是干细胞注射，而是 PRP 注射到头皮中，取得了一定的成功。

These are very expensive treatments.

这些都是非常昂贵的治疗方法。

They tend to be transiently successful.

他们往往会取得短暂的成功。

I'm sure there are people out there who are going to say, "PRP worked fabulously well for me." That might be the case.

我确信有人会说：“PRP 对我来说效果非常好。”情况可能就是这样。

I'm not going to dispute that, and I'm happy for you, although there are not sufficient clinical data to suggest PRP as a treatment right now, especially given the cost, many thousands of dollars, many, many treatments.

我不会对此提出异议，我为你感到高兴，尽管目前还没有足够的临床数据表明 PRP 作为一种治疗方法，特别是考虑到成本，数千美元，许多治疗方法。

It's also the case that the PRP injections- When they work, might work for reasons independent of the platelets.

事实也是如此，PRP 注射——当它们起作用时，可能会因为与血小板无关的原因而起作用。

What do I mean by that?

我这么说是什么意思？

Well, soon we're going to talk about a different type of treatment, which is a mechanical manipulation of the hair follicle, typically on the scalp, because that's typically where people want to regrow hair.

好吧，很快我们将讨论另一种不同类型的治疗方法，即对毛囊进行机械操作，通常是在头皮上，因为这通常是人们想要重新长出头发的地方。

I don't know many people who are trying to maintain or accelerate or regrow their back hair, for instance.

例如，我不知道有多少人试图保持或加速或重新长出背毛。

They might be out there, but I don't think there are a lot of them.

他们可能在那里，但我认为数量并不多。

Or their leg hair, for that matter.

或者他们的腿毛，就此而言。

Almost always it's going to be scalp hair.

几乎总是头皮上的毛发。

And one way that people are doing that is through mechanical stimulation of the hair follicle and the stem cell niche using what's called microneedling.

人们这样做的一种方法是使用所谓的微针对毛囊和干细胞生态位进行机械刺激。

Microneedling, as the name suggests, is taking a bunch of little needles, either in a little stamp, so a little square, or nowadays, typically it's a roller.

微针，顾名思义，就是采用一堆小针，要么是一个小邮票，所以有点方形，要么现在通常是一个滚轮。

So it looks like a paint roller, except it's got tons of little needles in rows all over that roller.

所以它看起来像一个油漆滚筒，只不过滚筒上布满了成排的大量小针。

Those needles range in length from half a millimeter to 2.5 millimeters.

这些针的长度从半毫米到 2.5 毫米不等。

Okay?

好的？

Millimeters.

毫米。

And one rolls that over the scalp, and if you're thinking, "Ouch, that probably hurts," indeed, it can hurt a little bit or a lot, depending on the thickness and the length of those needles.

然后将其滚过头皮，如果您想，“哎哟，这可能很痛”，事实上，它可能会有点痛或很痛，具体取决于这些针的粗细和长度。

Microneedling has been shown to do two things.

微针已被证明有两个作用。

It has been shown to reactivate semi-quiescent populations of stem cells that are in that telogen phase, putting them back in anagen phase, and thereby stimulate more hair growth.

它已被证明可以重新激活处于休止期的半静止干细胞群，使它们回到生长期，从而刺激更多的毛发生长。

It has also, and this is, I think, the best use of microneedling, it has also been shown to be a very effective augment for some of the hormone-based hair regrowth tools and pharmacology that we're going to talk about in a few minutes.

我认为这是微针的最佳用途，它也被证明是对一些基于激素的头发再生工具和药理学的非常有效的增强，我们将在几分钟后讨论。

So microneedling and PRP have something very critical in common, which is the needle, the actual injection into the skin.

因此，微针和 PRP 有一些非常关键的共同点，那就是针，即实际注射到皮肤中的方式。

And for those of you that are hearing this and thinking, "Why would disrupting the skin with needles actually support hair growth or regrowth?

对于那些听到这个并思考的人来说，“为什么用针破坏皮肤实际上会支持毛发生长或再生？

Wouldn't that just damage the follicle?" Well, this gets into some of the, I think, interesting, if not fascinating, aspects of our biology, which is that all of the cells in our body really can respond to both chemical and mechanical cues.

这不是会损伤毛囊吗？”嗯，我认为这涉及到我们生物学的一些有趣的（如果不是令人着迷的）方面，那就是我们体内的所有细胞确实都能对化学和机械线索做出反应。

And when we hear needle injected in the skin, we think, "Ah, that must just be damaging everything, causing all sorts of inflammation." But it turns out that low levels of inflammation caused by things like microneedling or PRP injections, or even the introduction of any kind of fluid, right?

当我们听到针头注入皮肤时，我们会想，“啊，这肯定会破坏一切，引起各种炎症。”但事实证明，微针或 PRP 注射，甚至引入任何液体都会引起低水平的炎症，对吗？

For instance, saline fluid injected into a region can cause changes in the cells in that region, causing, for instance, stem cell populations that were waning to reactivate again, causing telogen phase follicles that have melanocytes and stem cells that are dying off but not completely gone to re-enter the cell cycle.

例如，将盐水注射到某个区域可能会导致该区域的细胞发生变化，导致干细胞群再次重新激活，导致休止期毛囊的黑素细胞和干细胞死亡但尚未完全消失，从而重新进入细胞周期。

So microneedling procedures, PRP injections, things like minoxidil, they all kind of center around this same general theme of increasing blood flow, increasing oxygen, delivery of nutrients, or in the case of microneedling, increasing inflammation just enough at that local site that certain cascades of biological function that relate to proliferation of stem cells or maintenance of stem cell populations are kicked off.

因此，微针手术、PRP 注射、米诺地尔之类的东西，它们都围绕着同样的主题，即增加血流量、增加氧气、输送营养物质，或者在微针的情况下，增加局部部位的炎症，从而启动与干细胞增殖或干细胞群维持相关的某些生物功能级联。

It's sort of like reminding the cells in that area that they need to stay alive in order to replenish whatever is lost.

这有点像提醒该区域的细胞，它们需要保持活力才能补充损失的东西。

So sometimes a wound can actually induce some healing, although I do want to point out that the micro part of microneedling is absolutely key, and this should be obvious to you when you think about scars.

因此，有时伤口实际上可以促进一些愈合，尽管我确实想指出微针的微观部分绝对是关键，当您想到疤痕时，这一点对您来说应该是显而易见的。

I don't know about you, but I've never seen a scar with hair growing out of it.

我不知道你怎么想，但我从来没有见过有头发长出来的疤痕。

Or if there was, it was probably one hair.

或者即使有，也可能是一根头发。

But if you've ever seen a scar, for someone had their appendix out or if someone had a brain surgery, you see that scar because there is no hair growing out of it.

但如果你曾经见过疤痕，比如有人切除了阑尾，或者有人做过脑部手术，你就会看到疤痕，因为疤痕里没有头发长出来。

So the micro portion of microneedling is extremely important.

所以微针的微观部分极其重要。

We are not talking about causing significant damage to a tissue in order to activate that stem cell population.

我们并不是在谈论对组织造成重大损伤以激活干细胞群。

We're talking about causing microdamage and micro levels of inflammation to stimulate growth.

我们谈论的是通过造成微损伤和微炎症来刺激生长。

For those of you that are interested in using microneedling or microneedling in combination with chemical treatments like minoxidil or some of the other treatments we'll talk about in a little bit, like finasteride and caffeine.

对于那些对使用微针或微针与化学治疗（如米诺地尔）或其他一些治疗方法（如非那雄胺和咖啡因）结合感兴趣的人，我们将在稍后讨论。

Yes, believe it or not, caffeine is being used to regrow hair.

是的，不管你信不信，咖啡因被用来促进头发再生。

Very interesting.

非常有趣。

Get into that in a moment.

请稍后进行讨论。

But if you're interested in using microneedling alone or in combination with some of these other treatments, there's a wonderful review that was just published this last year.

但是，如果您对单独使用微针或与其他一些治疗方法结合使用感兴趣，可以阅读去年刚刚发表的一篇精彩评论。

Wonderful because it's very comprehensive.

很棒，因为它非常全面。

Not so wonderful, not to the fault of the authors, because most of the studies out there on microneedling are not superb.

并不是那么美妙，这不是作者的错，因为大多数关于微针的研究并不出色。

There are ways of gauging the strength of a study, mainly related to their duration, whether or not there were control groups, et cetera, but the review itself is excellent.

衡量研究强度的方法有很多，主要与研究的持续时间、是否有对照组等有关，但审查本身非常好。

And the title of the review is "Microneedling and Its Use in Hair Loss Disorders: A Systematic Review." We will provide a link to this in the show note captions.

这篇评论的标题是“微针及其在脱发疾病中的应用：系统评论”。我们将在节目注释标题中提供指向此内容的链接。

And this review did a very good job of highlighting both the strengths and drawbacks of the various studies looking at microneedling.

这篇综述很好地强调了有关微针的各种研究的优点和缺点。

It also explored the use of microneedling in both men and women and of various ages.

它还探索了微针在男性和女性以及不同年龄段的使用情况。

And it does appear to be the case that microneedling shows some positive benefit in both men and women, regardless of age, especially when used in combination with the various other treatments that we're talking about.

事实似乎确实如此，无论年龄大小，微针对男性和女性都显示出一些积极的益处，尤其是与我们正在讨论的各种其他治疗方法结合使用时。

I was also able to glean from this review and some of the papers described within it that needle lengths of about one millimeter to 2.5 millimeters seem to be more effective than shorter needle lengths.

我还从这篇评论和其中描述的一些论文中了解到，大约 1 毫米到 2.5 毫米的针长度似乎比较短的针长度更有效。

So if you're scared of the needles and the needle lengths, keep in mind that done properly, microneedling shouldn't be too painful.

因此，如果您害怕针头和针头长度，请记住，如果操作正确，微针不会太痛。

Some people experience a little bit more pain than others, but it's not considered a very painful procedure.

有些人会比其他人经历更多的疼痛，但这并不被认为是一个非常痛苦的过程。

It is, however, a procedure that can cause some bleeding of the scalp, and that bleeding of the scalp can be very apparent, especially if it's in the front of the head as opposed to on the top of the head and hidden by some hair, or if you're already ...

然而，这是一个可能导致头皮出血的手术，而且头皮出血可能非常明显，特别是如果它位于头前部而不是头顶并被一些头发隐藏，或者如果您已经......

quite bald in a given region.

在特定区域相当秃头。

So keep that in mind.

所以请记住这一点。

I suppose one could wear a hat or a wig or something of that sort if they were really self-conscious about it.

我想如果人们真的对此有自觉意识的话，他们可以戴一顶帽子或假发或类似的东西。

But the microneedling itself is causing a physical disruption to the scalp, some degree of bleeding, inflammation, and again, all of that is part of the process by which microneedling can actually improve hair growth.

但微针本身会对头皮造成物理破坏、一定程度的出血、炎症，而且所有这些都是微针实际上可以改善头发生长过程的一部分。

And of course, there's healing that occurs of the bleeding and the damage to the follicle.

当然，出血和毛囊损伤也会得到治愈。

This is a transient thing, but understanding the cosmetic implications in the short term as well as in the long term is certainly worth knowing.

这是一个短暂的事情，但了解短期和长期的外观影响确实值得了解。

One thing that's very clear is that the combination of microneedling and minoxidil treatment together is far more effective than either of those treatments alone.

非常清楚的一件事是，微针和米诺地尔治疗相结合比单独使用任何一种治疗方法更有效。

In addition, the combination of microneedling and minoxidil has been shown to be effective in recovering what are called dead zones.

此外，微针和米诺地尔的结合已被证明可以有效恢复所谓的死区。

So these are regions of the scalp that are either completely bald or mostly bald, for which there is essentially no stem cell population there, and the combination of minoxidil plus microneedling is somehow able to recover those stem cell populations and allow new hair to grow.

因此，这些头皮区域要么完全秃顶，要么大部分秃顶，那里基本上没有干细胞群，而米诺地尔加微针的组合能够以某种方式恢复这些干细胞群并让新头发生长。

Although, the growth of that hair in those dead zone regions can take a very long time, 30 to even 50 weeks.

尽管如此，那些死区区域的毛发生长可能需要很长的时间，30甚至50周。

Neither minoxidil treatment alone nor microneedling alone has been shown to be effective in recovering these so-called dead zones when those treatments are done separately.

当单独进行这些治疗时，单独的米诺地尔治疗或单独的微针治疗都没有被证明可以有效恢复这些所谓的死区。

So this, I would say, is a strong reason to consider combining microneedling and minoxidil as opposed to just doing minoxidil or just microneedling.

因此，我想说，这是考虑将微针和米诺地尔结合起来的一个强有力的理由，而不是仅仅使用米诺地尔或只是微针。

I should also mention that minoxidil treatment, if you pursue it, is likely something that you are going to have to do for the rest of your life if you want to hold on to the hair growth that you obtain with minoxidil, or if you want to maintain the hair that you are already maintaining with minoxidil.

我还应该提到，如果您追求米诺地尔治疗，如果您想保持使用米诺地尔获得的头发生长，或者如果您想维持已经使用米诺地尔维持的头发，那么您很可能将在余生中进行这种治疗。

Some people have been successful in taking minoxidil, maintaining some hair growth, or even stimulating some hair growth, and then coming off minoxidil.

有些人已经成功地服用米诺地尔，维持了一些头发生长，甚至刺激了一些头发生长，然后停止了米诺地尔。

But most everyone who goes on minoxidil has to stay on minoxidil because when they cease taking minoxidil, even if they're doing other treatments, they lose the hair that they gained with minoxidil.

但大多数服用米诺地尔的人都必须继续服用米诺地尔，因为当他们停止服用米诺地尔时，即使他们正在接受其他治疗，他们也会失去用米诺地尔获得的头发。

So that is an important consideration.

所以这是一个重要的考虑因素。

The decision to go on minoxidil is likely a decision to be on minoxidil for the rest of your life.

继续使用米诺地尔的决定很可能意味着您将终生使用米诺地尔。

So as you're probably starting to realize, there's a relationship between mechanical stimulation of the follicle and blood flow, both of which turn out to be critical for maintaining hair and for stimulating hair growth.

因此，您可能已经开始意识到，毛囊的机械刺激和血液流动之间存在关系，这两者对于维持头发和刺激头发生长都至关重要。

Not surprisingly then, an increasingly common treatment for hair loss is Botox.

毫不奇怪，越来越常见的脱发治疗方法是肉毒杆菌。

Botox is the brand name for what is otherwise known as botulinum neurotoxin.

Botox 是肉毒杆菌神经毒素的品牌名称。

What is botulinum neurotoxin?

什么是肉毒杆菌神经毒素？

Well, botulinum neurotoxin, sometimes just called botulinum for short, is a toxin that's a bacterial toxin that serves to cut the protein that leads to synaptic vesicle release.

肉毒杆菌神经毒素，有时简称为肉毒杆菌，是一种细菌毒素，可以切割导致突触小泡释放的蛋白质。

What in the world did I just say?

我刚才到底说了什么？

Well, when your nerve cells communicate with one another, they do that by way of electricity, but the electricity within those nerve cells, those neurons, triggers the release of chemicals from neurons into the synapse, the little gap between neurons.

嗯，当你的神经细胞相互交流时，它们是通过电的方式进行的，但是这些神经细胞、神经元内的电会触发化学物质从神经元释放到突触，即神经元之间的小间隙。

And the release of those chemicals allows the next neuron to be chemically active, or in some cases, it will suppress the electrical activity of that next neuron.

这些化学物质的释放使下一个神经元具有化学活性，或者在某些情况下，它会抑制下一个神经元的电活动。

Botulinum neurotoxin serves to cut a protein present in neurons so that neurons cannot release the chemicals that cause other neurons to be active.

肉毒杆菌神经毒素可以切割神经元中存在的蛋白质，使神经元无法释放导致其他神经元活跃的化学物质。

So this actually is pretty serious.

所以这实际上是非常严重的。

If you were to get botulinum neurotoxin injected into your muscle, you would be paralyzed because the nerves that control contraction of the muscles would not be able to control the release of that chemical onto the muscle, which makes it contract.

如果你将肉毒杆菌神经毒素注射到你的肌肉中，你就会瘫痪，因为控制肌肉收缩的神经将无法控制该化学物质释放到肌肉上，从而导致肌肉收缩。

Now, botulinum neurotoxin is commonly used in what's called Botox.

现在，肉毒杆菌神经毒素通常被称为肉毒杆菌毒素。

Botox is something most people are familiar with because people get it injected in and around their wrinkles.

肉毒杆菌是大多数人都熟悉的东西，因为人们将其注射到皱纹内和周围。

Because many wrinkles are triggered by not just loss of tensile strength in the skin, but rather the nerves around the skin and in the skin are hypercontracted, which causes wrinkles.

因为许多皱纹不仅是由于皮肤拉伸强度丧失而引发的，而且是由于皮肤周围和皮肤内的神经过度收缩而引起的，从而导致皱纹。

So for instance, I have crow's feet.

举例来说，我有鱼尾纹。

I like to think that's because I've laughed a lot and smiled a lot, and it's probably also because I've squinted a lot in my lifetime.

我喜欢认为那是因为我笑了很多，笑了很多，也可能是因为我一生中眯了很多次。

I have crow's feet because the nerves there have pinched the skin on either side of my eyes, and that's given me little creases there that are sometimes referred to as crow's feet.

我有鱼尾纹，因为那里的神经挤压了我眼睛两侧的皮肤，这让我的眼睛出现了小皱纹，有时被称为鱼尾纹。

Botox injections can be applied to the scalp in order to relieve tension of the scalp.

可以在头皮上注射肉毒杆菌，以缓解头皮的紧张。

And in hearing that, it should be obvious why Botox is being used to try and offset hair loss.

听到这个，应该很明显为什么要使用肉毒杆菌来尝试抵消脱发。

It's decreasing the squinting, if you will, or the tensile nature of the scalp skin so that more blood flow can arrive at that stem cell follicle area.

如果你愿意的话，它可以减少眯眼或头皮皮肤的拉伸性质，以便更多的血流可以到达干细胞毛囊区域。

So Botox treatment to the scalp is actually becoming pretty common.

因此，对头皮进行肉毒杆菌治疗实际上变得相当普遍。

There are a couple requirements with this Botox treatment.

这种肉毒杆菌治疗有几个要求。

First of all, it has to be done by somebody who's really skilled.

首先，它必须由真正熟练的人来完成。

There are numerous images online and websites online of so-called Botox fails, where people have gotten too much Botox, or the injections have been done too deep or not at the correct locations on people's face or scalp, and it can give them droopy scalp or droopy eyes.

网上和网站上有很多所谓的肉毒杆菌失败的图片，人们注射了过多的肉毒杆菌，或者注射得太深或注射位置不正确，导致头皮或眼睛下垂。

All sorts of cosmetic nightmares can occur with Botox.

肉毒杆菌可能会导致各种美容噩梦。

The second thing to understand is that Botox does eventually wear off.

第二件需要了解的事情是，肉毒杆菌最终会消失。

That botulinum neurotoxin doesn't stick around forever.

肉毒杆菌神经毒素不会永远存在。

And provided it's done correctly at the correct dosages, it doesn't actually kill the neurons that cause that tension of the skin, so Botox injections have to be done repeatedly.

如果以正确的剂量正确完成，它实际上不会杀死导致皮肤紧张的神经元，因此肉毒杆菌注射必须重复进行。

The efficacy of Botox for offsetting hair loss is not clear.

肉毒杆菌对抗脱发的功效尚不清楚。

There aren't a lot of large-scale clinical studies on this just yet, but it does seem to be at least one reasonably safe alternative to things like minoxidil.

目前还没有很多大规模的临床研究，但它似乎至少是米诺地尔等药物的一种相当安全的替代品。

Although, I think if one were to just want to increase blood flow to the scalp, things like low-dose tadalafil, which doesn't seem to carry any of the side effects that minoxidil can carry, we talked about those side effects earlier, that would probably be the better alternative.

不过，我认为如果只是想增加头皮的血流量，像低剂量他达拉非这样的东西，它似乎不会带来米诺地尔可能带来的任何副作用，我们之前讨论过这些副作用，那可能是更好的选择。

Botox is a fairly invasive procedure, but some people opt for Botox treatment.

肉毒杆菌是一种相当侵入性的手术，但有些人选择肉毒杆菌治疗。

In fact, there's a syndrome Called cutis verticis gyrata.

事实上，有一种综合症，叫做回状皮肤。

Some of you have probably seen this.

你们中有些人可能已经看过这个。

It's more typical in men, although it does occur in women.

尽管它确实发生在女性中，但它在男性中更为常见。

It literally means a lumping of the skin on the scalp or gyri of the scalp.

它的字面意思是头皮或头皮回上的皮肤肿块。

Gyri or gyrus pertains to the Latin word knee, so it means bump or knee.

Gyri 或 gyrus 属于拉丁词膝盖，所以它的意思是碰撞或膝盖。

And so any time you hear the word gyra in neuroscience or in biology, you're talking about a bump.

因此，每当你在神经科学或生物学中听到“回旋”这个词时，你所谈论的就是“颠簸”。

You sometimes see people have ridges in the back, or it looks as if the skin was pushed together, kind of like a Shar Pei dog, but on the scalp.

有时你会看到人们的背部有脊，或者看起来皮肤被挤在一起，有点像沙皮狗，但在头皮上。

People with cutis verticis gyrata almost always experience pattern hair loss.

患有头回型皮肤的人几乎总是会经历脱发。

Now, part of the reason for that is cutis verticis gyrata is also associated with some androgen or testosterone-related hormone issues that we'll talk about in a little bit.

现在，部分原因是头状皮回还与一些雄激素或睾酮相关的激素问题有关，我们稍后会讨论这些问题。

But in addition to that, it has been shown that relieving some of those gyrata by injections of Botox to allow those folds to sit flatter, A, is effective.

但除此之外，事实证明，通过注射肉毒杆菌来缓解部分回旋，让这些褶皱变得更平坦，A，是有效的。

It can lead to less of those gyri, those bumps, and can improve hair growth in those regions, even if those people don't take on any additional treatments to address the hormone issues.

它可以减少这些脑回、那些肿块，并可以改善这些区域的毛发生长，即使这些人没有采取任何额外的治疗来解决激素问题。

So that's really how people arrived at this understanding that Botox might be a good treatment in general for reducing the kind of squinting of the scalp that can occur and the resulting hair loss in those regions.

这就是人们真正认识到肉毒杆菌可能是一种很好的治疗方法，可以减少可能发生的头皮斜视以及由此导致的脱发。

I'd now like to turn our attention to the chemical variables that control the duration of the growth phase of hair, the duration of that catagen phase, which is when that hair essentially recedes from the inside out, and the quiescent or semi-quiescent telogen phase.

现在我想把我们的注意力转向控制头发生长阶段持续时间的化学变量，退行期的持续时间，即头发基本上从内向外退缩的时间，以及静止或半静止休止期。

There are a couple of key chemical players here that we should all be aware of.

这里有几个我们都应该注意的关键化学参与者。

First of all, the growth factor, IGF-1, insulin growth factor one, which is produced by the liver, but that receives stimulation from the brain and pituitary to be released, is a strong regulator of hair growth, and we can think of it as the accelerator on hair growth.

首先，生长因子，IGF-1，胰岛素生长因子一，由肝脏产生，但受到大脑和垂体的刺激而释放出来，是头发生长的强力调节剂，我们可以将其视为头发生长的加速器。

So it does that by extending that anagen or growth phase for longer.

因此，它通过延长生长期或生长期来实现这一点。

It doesn't necessarily speed up growth, but it extends it for a longer period of time.

它不一定会加速增长，但会延长增长的时间。

In addition, cyclic AMP, which is part of what's called a second messenger pathway, in fact, cyclic AMP is a second messenger, is also a key player in stimulating growth of the hair follicle.

此外，环磷酸腺苷是所谓的第二信使途径的一部分，事实上，环磷酸腺苷是第二信使，也是刺激毛囊生长的关键因素。

Now, cyclic AMP does many different things in many different cell types in the body.

现在，环磷酸腺苷在体内许多不同的细胞类型中发挥许多不同的作用。

It really acts, as the name suggests, as a messenger between signals that arrive at the surface of cells and transmitting or conveying those signals to things that happen deep within the cells, such as the turning on and off of various genes.

顾名思义，它确实充当到达细胞表面的信号与将这些信号传递或传达到细胞深处发生的事情（例如各种基因的打开和关闭）之间的信使。

So when you hear second messenger, don't let that confuse you or overwhelm you.

因此，当您听到第二个信使时，不要让它让您感到困惑或不知所措。

Just understand that the whole process of getting signals from the outside of cells into the center of cells and controlling gene expression, for instance, causing a stem cell to continue to give off daughter cells or causing a hair cell to continue growing for longer, that whole process is a bit like a bucket brigade of handing off water or a bucket from one component to the next or along a chain.

只要理解从细胞外部获取信号到细胞中心并控制基因表达的整个过程，例如，使干细胞继续释放子细胞或使毛细胞继续生长更长时间，整个过程有点像水桶队或沿着链条将水或水桶从一个组件传递到下一个组件。

It's like an assembly line.

这就像一条装配线。

I think that's probably the simplest way to think about it.

我认为这可能是最简单的思考方式。

So for sake of this discussion, IGF-1 is known to increase the growth of hair by extending that anagen phase, as is cyclic AMP.

因此，为了便于讨论，已知 IGF-1 可以通过延长毛发生长初期阶段来促进毛发生长，环磷酸腺苷也是如此。

So those are going to be considered the accelerators, at least in this conversation.

因此，至少在本次对话中，这些将被视为加速器。

The brakes on hair growth are going to be the things that either shorten the anagen phase or that extend the catagen phase or this quiescent phase, which is the telogen phase.

毛发生长的阻碍将是缩短毛发生长初期或延长毛发生长中期或静止期（即毛发生长终期）。

And the two major brakes on hair growth that we want to think about are PDE, which is a phosphodiesterase.

我们要考虑的两个阻碍头发生长的主要因素是磷酸二酯酶（PDE），它是一种磷酸二酯酶。

Okay?

好的？

Anytime you hear ase, it's likely to be an enzyme.

每当您听到 ase 时，它​​很可能是一种酶。

And TGF beta 2.

和TGFβ2。

All right?

好吧？

So this is a particular growth factor that somewhat counterintuitively doesn't stimulate growth, it actually stimulates lack of growth or shortens growth.

因此，这是一种特殊的生长因子，有点违反直觉，它不会刺激生长，它实际上会刺激生长不足或缩短生长。

So with all of that in mind, and please do also keep in mind that you don't need to remember all those specific terms.

因此，考虑到所有这些，还请记住，您不需要记住所有这些特定术语。

Just understand that there are some factors, like insulin growth factor one, that act as accelerators on growth, and there are factors that act as brakes on growth.

只需要明白，有些因素（例如胰岛素生长因子一）可以促进生长，也有一些因素可以抑制生长。

We can start to think about why, for instance, half of all people by age 50 start to lose their hair.

例如，我们可以开始思考为什么一半的人在 50 岁时开始脱发。

Well, they start to lose their hair because of something called androgen-related alopecia, which translated to English means testosterone and testosterone derivative-induced hair loss.

好吧，他们开始脱发是因为一种叫做雄激素相关性脱发的疾病，翻译成英语就是睾酮和睾酮衍生物引起的脱发。

This is true in men and women.

这对于男性和女性来说都是如此。

So hearing that, you should probably be wondering the following thing.

听到这里，您可能应该想知道以下事情。

Young men have higher levels of testosterone than old men, right?

年轻人的睾丸激素水平比老年人高，对吗？

Well, the answer is yes, although some older men in their 40s, 50s, even 80s, maintain testosterone levels similar to many men in their 20s.

答案是肯定的，尽管一些 40 多岁、50 多岁、甚至 80 多岁的老年男性仍保持着与许多 20 多岁男性相似的睾酮水平。

But most don't.

但大多数人没有。

It's a downward slope, starting at about age 40.

从40岁左右开始，这是一个下降的趋势。

How steep that downward slope is depends.

下降的斜率有多陡取决于。

Women, too, have testosterone.

女性也有睾丸激素。

In fact, women have higher levels of testosterone than they do estrogen.

事实上，女性的睾酮水平高于雌激素水平。

That's right.

这是正确的。

A healthy woman has higher levels of testosterone than she does estrogen.

健康女性的睾酮水平高于雌激素水平。

However, women on average have lower testosterone than most men.

然而，女性的睾酮水平平均低于大多数男性。

Okay?

好的？

So they still have far more estrogen and far less testosterone than most men, but the level of testosterone that they have within their body is higher than the level of estrogen they have.

因此，他们的雌激素水平仍然比大多数男性高得多，而睾酮水平却远低于大多数男性，但他们体内的睾酮水平却高于雌激素水平。

Androgens, such as testosterone and its derivatives, such as dihydrotestosterone, which will be much the topic of what we're getting into next, inhibit IGF-1 and cyclic AMP.

雄激素，例如睾酮及其衍生物，例如二氢睾酮（这将是我们接下来要讨论的主题）会抑制 IGF-1 和环 AMP。

Again, androgens such as dihydrotestosterone inhibit, prevent the action of IGF-1 and cyclic AMP, which you just learned a few moments ago, act to extend the anagen or growth phase of hair.

同样，二氢睾酮等雄激素会抑制、阻止 IGF-1 和环 AMP 的作用，您刚才刚刚了解到，它们可以延长头发的生长期或生长期。

Which then raises the question, well, if young people both male and female have higher levels of testosterone than they do when they're older, why would people lose their hair when they're older and not younger?

这就提出了一个问题，如果年轻人和女性的睾丸激素水平都比年长时高，为什么人们会在年老而不是年轻时脱发？

Ah.

啊。

The answer lies in the conversion of testosterone to dihydrotestosterone.

答案在于睾酮转化为二氢睾酮。

Testosterone, most people have heard of.

睾酮，大多数人都听说过。

Dihydrotestosterone, or DHT, is made from testosterone.

二氢睾酮（DHT）是由睾酮制成的。

There's an enzyme called 5-alpha reductase that converts testosterone into dihydrotestosterone in both men and women.

有一种叫做 5-α 还原酶的酶，可以将男性和女性的睾酮转化为二氢睾酮。

Dihydrotestosterone binds to the androgen receptor at five times the affinity of testosterone, so it is the most powerful androgen in humans, and it is responsible for a number of things that we all really want and like, such as mental vigor, physical vigor, strength, healing capacity, drive, libido, and on and on.

二氢睾酮与雄激素受体的结合亲和力是睾酮的五倍，因此它是人类中最强大的雄激素，它负责许多我们真正想要和喜欢的事情，例如精神活力、身体活力、力量、治愈能力、驱动力、性欲等等。

So DHT itself is not bad.

所以DHT本身也不错。

So if we take a step back and we acknowledge testosterone levels are higher in males and females at younger ages as opposed to older, but as they get older, there is more 5-alpha reductase activity, which is converting more of that testosterone to dihydrotestosterone, and dihydrotestosterone inhibits hair growth by reducing IGF-1 and cyclic AMP, well, then we should all be aboard why it is that by age 50, about 50% of people experience pattern hair loss.

因此，如果我们退后一步，承认男性和女性在年轻时的睾酮水平高于年长者，但随着年龄的增长，5-α还原酶活性会增加，从而将更多的睾酮转化为二氢睾酮，而二氢睾酮通过减少 IGF-1 和环磷酸腺苷来抑制头发生长，那么我们都应该明白为什么到 50 岁时，大约 50% 的人会出现脱发。

That is androgen-dependent alopecia.

这就是雄激素依赖性脱发。

Okay?

好的？

But translated to normal English is pattern hair loss.

但翻译成普通英语就是“模式脱发”。

And in a moment, you'll understand why some people lose their hair from the crown region, in the back of the head, or back and top of the head, whereas other people lose their hair in the front of their head, in the flanks right on either side of the midline or maybe in the midline in front altogether.

过一会儿，你就会明白为什么有些人会在头顶、后脑勺、后脑勺脱发，而另一些人会在头前部、中线两侧的侧翼、甚至前面的中线脱发。

And that's because different people, depending on their genetic lineage, have different patterns of androgen receptors on their scalp.

这是因为不同的人，根据他们的遗传谱系，头皮上的雄激素受体模式也不同。

And the pattern of androgen receptors that you inherit indeed does come from your mother's side.

你继承的雄激素受体模式确实来自你母亲的一侧。

And so this is what gave rise to the myth that if you want to know if you're going to go bald or not, just look at your mother's father.

因此，这就是产生这样一个神话的原因：如果你想知道自己是否会秃头，只要看看你的母亲的父亲就可以了。

Doesn't quite work that way.

不太行得通。

In fact, if you think about the logic, you should really look at your mother's mother if you want to know your pattern of androgen receptors on your scalp.

事实上，如果你考虑一下逻辑，如果你想知道你头皮上雄激素受体的模式，你真的应该看看你母亲的母亲。

However, most women don't lose as much hair from their scalp, or they have ways of covering up the hair loss in their scalp because their hair is just generally longer or they're using other approaches, so that you never really get a clear picture of what the androgen-dependent hair loss was in your grandmother.

然而，大多数女性头皮上的脱发并没有那么多，或者她们有办法掩盖头皮上的脱发，因为她们的头发普遍较长，或者她们正在使用其他方法，所以你永远无法真正清楚地了解你祖母的雄激素依赖性脱发是什么。

Okay?

好的？

Now we don't want to go too far down the genetics rabbit hole because, as you know, you can't select your parents anyway, but if you want to know why, for instance, I'm losing a bit of hair on either side of the midline in the front, it almost certainly has to do with the fact that I have a higher density of androgen receptors there as opposed to, say, on the crown of my head, where, for whatever reason, my hair seems to grow thickest.

现在我们不想在遗传学的兔子洞里走得太远，因为，正如你所知，你无论如何都无法选择你的父母，但如果你想知道为什么，例如，我在前中线两侧失去了一点头发，这几乎肯定与我在那里的雄激素受体密度更高这一事实有关，而不是在我的头顶上，无论出于何种原因，我的头发似乎长得最厚。

Other people lose hair on the crown, in the back and top, but not in the front, and some people lose it all over.

有些人的头发在头顶、后面和顶部脱发，但前面没有，有些人则全身脱发。

Now you understand why hair loss occurs in certain regions of the body.

现在您了解为什么身体的某些部位会出现脱发了。

You should also understand that the androgen receptors on the face are also what are responsible for beard growth, and this is where it can get a little bit tricky, but a lot of things will start to make sense if you can understand this and internalize this.

你还应该明白，脸上的雄激素受体也是胡须生长的原因，这就是它可能会变得有点棘手的地方，但如果你能理解这一点并将其内在化，很多事情就会开始变得有意义。

If you have a high density of androgen receptors on your face, well then, as your DHT levels go up with age, you will be able to grow a thicker and thicker beard.

如果你脸上的雄激素受体密度很高，那么，随着你的 DHT 水平随着年龄的增长而上升，你的胡须就会越来越浓密。

In fact, it is rare to see someone who can grow a thick beard in their youth, but not so much as they get older.

事实上，年轻时能留出浓密胡须的人很少见，但随着年龄的增长就更少见了。

In fact, the reverse tends to be true.

事实上，事实往往恰恰相反。

So the pattern of androgen receptors differs between the scalp and the face and the back.

因此，头皮、面部和背部的雄激素受体模式是不同的。

Okay?

好的？

On your back, you have androgen receptors, and there, DHT stimulates hair growth.

在你的背部，你有雄激素受体，在那里，双氢睾酮会刺激毛发生长。

So if you know someone who has a very hairy back or if you have a very hairy back, that means you have a high density of androgen receptors on your back.

因此，如果您认识某人的背部毛茸茸的，或者您的背部毛茸茸的，则意味着您的背部有高密度的雄激素受体。

If you have a beard and that beard is thick, well then you have a high density of androgen receptors on your face.

如果你有胡子并且胡子很厚，那么你脸上的雄激素受体密度就很高。

However, a high density of androgen receptors anywhere on your scalp is going to predispose those regions to androgen-dependent alopecia or hair loss in those particular regions, which is going to allow us to understand why all of the rest of the treatments for halting hair loss and for stimulating hair growth, almost all of those center on inhibiting either DHT directly or 5-alpha reductase, the conversion of testosterone to DHT.

然而，头皮上任何地方的高密度雄激素受体将使这些区域容易患上雄激素依赖性脱发或特定区域的脱发，这将使我们能够理解为什么所有其他阻止脱发和刺激头发生长的治疗方法，几乎​​所有这些治疗都集中在直接抑制 DHT 或 5-α 还原酶（睾酮向 DHT 的转化）。

So now I'd like to discuss the ways that one can chemically adjust certain things within the hair growth pathway, things like IGF-1, PDE, TGF-beta, et cetera, in order to stimulate hair growth or halt hair loss.

现在我想讨论一下如何通过化学方法调节头发生长途径中的某些物质，例如 IGF-1、PDE、TGF-β 等，以刺激头发生长或阻止脱发。

The first thing on this list is actually going to be pretty surprising to a number of you, and that's caffeine.

这份清单上的第一件事实际上会让你们中的许多人感到非常惊讶，那就是咖啡因。

We all think of caffeine as a stimulant that we drink.

我们都认为咖啡因是我们喝的兴奋剂。

I certainly drink coffee and yerba mate, the occasional energy drink, things of that sort.

我当然会喝咖啡和马黛茶，偶尔也会喝能量饮料之类的东西。

Caffeine does many things besides stimulate our central nervous system and make us feel less sleepy, however.

然而，咖啡因除了刺激我们的中枢神经系统和让我们感觉不那么困之外，还有很多作用。

One of the things that caffeine does is it is a fairly potent PDE inhibitor.

咖啡因的作用之一是它是一种相当有效的 PDE 抑制剂。

By being a potent PDE inhibitor, it indirectly stimulates IGF-1.

作为一种有效的 PDE 抑制剂，它可以间接刺激 IGF-1。

Why?

为什么？

Well, because PDE can suppress IGF-1, and by ingesting caffeine or by applying topical caffeine ointment or cream to the scalp, you can suppress PDE sufficiently enough to increase IGF-1 and increase some hair growth or at least maintain hair growth in that region.

嗯，因为 PDE 可以抑制 IGF-1，通过摄入咖啡因或在头皮上涂抹外用咖啡因软膏或霜，您可以充分抑制 PDE，从而增加 IGF-1 并增加一些头发生长或至少维持该区域的头发生长。

Now this may come as a shock.

现在这可能会令人震惊。

It might seem a little bit esoteric or even outside the margins of typical treatments, but head-to-head, topical caffeine application can be as effective as minoxidil application without actually lowering things like blood pressure and potentially increasing prolactin and some of the other negative, let's call them negative because they are, side effects of minoxidil.

这可能看起来有点深奥，甚至超出了典型治疗的范围，但面对面的局部咖啡因应用可以与米诺地尔应用一样有效，而不会真正降低血压和潜在增加催乳素等其他负面影响，让我们称它们为负面影响，因为它们是米诺地尔的副作用。

So caffeine ointments and caffeine present in various hair treatments and creams, et cetera, is starting to become a more prominent theme out there I will include a reference to caffeine and its uses for offsetting hair loss.

因此，咖啡因软膏和咖啡因存在于各种头发护理和面霜等中，开始成为一个更突出的主题，我将提及咖啡因及其用于抵消脱发的用途。

Keep in mind that topical caffeine ointments shouldn't necessarily be applied every single day.

请记住，外用咖啡因软膏不一定每天都使用。

So this is the sort of thing you might do three times a week.

所以这是你每周可以做三次的事情。

The concentration of caffeine in different ointments varies tremendously.

不同药膏中咖啡因的浓度差异很大。

Most of the studies of caffeine on the stem cell niches that control hair growth and extension of the anagen phase of hair growth have been performed in vitro in a dish.

大多数咖啡因对控制毛发生长和毛发生长初期延长的干细胞生态位的研究都是在体外培养皿中进行的。

Although there are some clinical studies exploring this, they are not nearly as extensive in number or duration as the studies of minoxidil because this approach just hasn't been around quite as long.

尽管有一些临床研究对此进行了探索，但它们的数量或持续时间并不像米诺地尔的研究那么广泛，因为这种方法出现的时间还不够长。

However, when comparing side effects of minoxidil, cost of minoxidil, comparing the efficacy of caffeine and minoxidil, I think caffeine as a topical treatment for offsetting hair loss stands as a pretty good choice if you're going to start exploring this pathway.

然而，当比较米诺地尔的副作用、米诺地尔的成本、比较咖啡因和米诺地尔的功效时，我认为如果你要开始探索这条途径，咖啡因作为抵消脱发的局部治疗方法是一个不错的选择。

And there's no reason to think that if you were to try the caffeine ointment and it didn't work for you or you didn't like it for some reason or you needed to stop it for some reason, that you couldn't stop it safely because it doesn't carry all the other blood pressure-related effects and prolactinemia effects that minoxidil does.

而且没有理由认为，如果您尝试使用咖啡因软膏，但它对您不起作用，或者由于某种原因您不喜欢它，或者由于某种原因您需要停止使用它，那么您就无法安全地停止使用它，因为它不具有米诺地尔所具有的所有其他与血压相关的作用和催乳素血症作用。

So if you look out there into the hair maintenance and hair replacement literature, and you look at the treatments that are being sold, don't be surprised to see caffeine there.

因此，如果您查阅有关头发保养和头发替换的文献，并查看正在出售的治疗方法，您会发现其中含有咖啡因，请不要感到惊讶。

And also, don't be surprised when I tell you what I'm about to tell you now, which is, no, you can't simply just drink more caffeine in order to accomplish the goal of offsetting hair loss.

而且，当我告诉你我现在要告诉你的事情时，不要感到惊讶，那就是，不，你不能简单地喝更多的咖啡因来实现抵消脱发的目标。

It is true that when you ingest caffeine, it goes systemically.

确实，当你摄入咖啡因时，它会进入全身。

However, you have so many adenosine receptors throughout your body.

然而，您的体内有如此多的腺苷受体。

Those adenosine receptors and the parking of caffeine in those adenosine receptors is the main way in which caffeine exerts its stimulatory effects, making you feel less sleepy.

这些腺苷受体和咖啡因在这些腺苷受体中的停留是咖啡因发挥其刺激作用的主要方式，使您感觉不那么困。

So it does that because then adenosine can't have its effects, which are to make you sleepy.

之所以这样做，是因为腺苷就无法发挥其让你昏昏欲睡的作用。

Well, those adenosine receptors soak up so much of the caffeine that you would ingest orally that very, very little would make it to the scalp and to the hair follicles at the concentrations that you would want.

嗯，这些腺苷受体吸收了如此多的咖啡因，以至于你口服摄入的咖啡因很少，很少能以你想要的浓度到达头皮和毛囊。

So that's why you have to rely on the application of these caffeine ointments about three times a week.

这就是为什么您必须每周使用这些咖啡因软膏大约三次。

Keep in mind that no one has really explored the dosages of caffeine in these ointments in a systematic way.

请记住，没有人真正系统地研究过这些药膏中咖啡因的剂量。

We're still in the early stages of all this.

我们仍处于这一切的早期阶段。

But I do think it's important to mention caffeine because of the lower incidence of side effects, at least reported side effects, and the general safety margins and the head-to-head, essentially comparable efficacy with minoxidil because minoxidil has a bunch of other issues.

但我确实认为提及咖啡因很重要，因为副作用的发生率较低，至少报告的副作用，以及一般安全裕度和头对头，与米诺地尔的功效基本上相当，因为米诺地尔还有很多其他问题。

Now keep in mind that both minoxidil and caffeine are generally used as a preventative for reducing hair loss over time.

现在请记住，米诺地尔和咖啡因通常都用作减少脱发的预防剂。

They are not expected, and they do not, as far as we know, create new hair growth to any sufficient degree.

据我们所知，它们并没有达到任何足够的程度，也没有产生新的毛发生长。

If any of you have used caffeine ointments or minoxidil and observed new hair growth that was robust, please put that in the comments section.

如果你们中有人使用过咖啡因软膏或米诺地尔并观察到新的毛发生长强劲，请在评论部分留言。

I'd be curious about those experiences.

我对这些经历很好奇。

But as far as I know and from the clinical literature that I read, there's no examples of that.

但据我所知和我阅读的临床文献，没有这样的例子。

One other point about caffeine, it does appear that caffeine can not only indirectly stimulate IGF-1 in the anagen phase of hair cell growth by way of reducing PDE and TGF-beta, but it also seems to reduce apoptosis, which is naturally occurring cell death of that stem cell niche.

关于咖啡因的另一点是，咖啡因不仅可以通过减少 PDE 和 TGF-β 来间接刺激毛细胞生长的生长期中的 IGF-1，而且似乎还可以减少细胞凋亡，这是干细胞生态位自然发生的细胞死亡。

We've been talking a lot about the anagen or growth phase of hair.

我们一直在谈论头发的生长期或生长期。

We also talked about the catagen, or the recession of that hair from the inside out.

我们还讨论了头发的退行期，即头发从内到外的衰退。

But remember that third phase, the telogen phase, where that whole bulb down at the bottom, the bulges it's called, gets pinched off and the whole thing dies and takes the stem cells off to the grave with it?

但还记得第三阶段，即休止期，整个球茎下降到底部，即所谓的凸起，被夹断，整个球茎死亡，干细胞也随之进入坟墓？

It appears that caffeine can offset the death of that niche and potentially maintain the stem cell population longer, making caffeine a really good choice to think about in conjunction with the various chemical treatments aimed at directly attacking the DHT pathway that we'll talk about next.

咖啡因似乎可以抵消该生态位的死亡，并有可能更长时间地维持干细胞群，这使得咖啡因成为与各种旨在直接攻击 DHT 途径（我们接下来将讨论）的化学治疗相结合的非常好的选择。

So there's one very direct way to increase hair growth and maintain the hair that you have on your head, and that's to increase IGF-1.

因此，有一种非常直接的方法可以促进头发生长并维持头发的健康，那就是增加 IGF-1。

That can be accomplished through prescription drugs such as growth hormone and things that stimulate the release of growth hormone and IGF-1.

这可以通过生长激素等处方药以及刺激生长激素和 IGF-1 释放的药物来实现。

Keep in mind, growth hormone is released from the anterior pituitary during the first hours of sleep, especially when you haven't eaten anything for the two hours prior to sleep, and especially when you get regular bedtimes.

请记住，生长激素会在睡眠的最初几个小时内从垂体前叶释放，特别是当您在睡前两个小时内没有吃任何东西时，尤其是当您有规律的就寝时间时。

Yes, this is a real thing.

是的，这是真实的事情。

If you are going to sleep at variable bedtimes, especially if you go to sleep much later than your usual habitual bedtime, you will miss that growth hormone pulse that normally occurs in the first two to three hours of sleep.

如果您打算在不同的就寝时间睡觉，特别是如果您比平时习惯的就寝时间晚得多，您就会错过通常在睡眠的前两到三个小时内出现的生长激素脉冲。

This does not mean that you need to be neurotic about getting to sleep at the exact same time every night.

这并不意味着您需要对每晚在同一时间入睡感到神经质。

There's probably a plus or minus 30-minute window.

可能有正负 30 分钟的窗口期。

And it doesn't mean that you can't stay out late or have a bad night's sleep every once in a while or get woken up.

这并不意味着您不能在外面熬夜或偶尔睡不好或被吵醒。

Your hair isn't going to fall out.

你的头发不会脱落。

My dad's story notwithstanding.

尽管有我父亲的故事。

Your hair isn't going to all fall out because of that.

你的头发不会因此而全部脱落。

But you do want to try and get that natural growth hormone release each night.

但您确实想尝试每晚释放自然生长激素。

And as I mentioned, there are prescription approaches, and those are growth hormone itself and things like sermorelin, which is a peptide that increases growth hormone.

正如我所提到的，有一些处方方法，这些方法是生长激素本身以及舍莫瑞林（一种可以增加生长激素的肽）之类的东西。

It's actually a secretagogue.

它实际上是一个秘密促进者。

It causes the secretion of growth hormone and thereby increases in IGF-1.

它引起生长激素的分泌，从而增加 IGF-1。

This is well-documented.

这是有据可查的。

Both growth hormone and IGF-1, as I mentioned, are available by prescription.

正如我提到的，生长激素和 IGF-1 都可以通过处方获得。

They are not without their side effects.

它们并非没有副作用。

So they do cause growth of all tissues.

所以它们确实会导致所有组织的生长。

They do increase height in children.

它们确实会增加儿童的身高。

They increase bone mass and density.

它们增加骨量和密度。

They can increase mainly fat loss, not so much muscle size, but they can increase leanness, and they increase hair growth.

它们主要可以增加脂肪的减少，而不是增加肌肉的大小，但它们可以增加瘦肉，并且可以增加头发的生长。

They can increase turnover of skin.

它们可以增加皮肤的更新。

They can make skin look more youthful.

它们可以使皮肤看起来更年轻。

All these things sound wonderful, and yet they also have problems because they can increase growth of small tumors that normally might be eliminated.

所有这些听起来都很美妙，但它们也有问题，因为它们会增加通常可以被消除的小肿瘤的生长。

So there is an increased cancer risk with growth hormone treatments in IGF-1 or anything that increases IGF-1, such as sermorelin, ipamorelin, any of the peptides that you hear about nowadays.

因此，使用 IGF-1 或任何增加 IGF-1 的生长激素治疗（例如舍莫瑞林、伊帕瑞林以及您现在听说的任何肽）会增加患癌症的风险。

That said, a number of people are using sermorelin as an indirect way to increase IGF-1 and thereby to increase hair growth.

也就是说，许多人使用舍莫瑞林作为增加 IGF-1 的间接方法，从而促进头发生长。

It does seem to be fairly effective in doing that, especially when done in conjunction with other treatments that we'll talk about.

它似乎确实相当有效，尤其是与我们将要讨论的其他治疗方法结合使用时。

But keep in mind, these are prescription drugs, and they do carry their own risks The other thing about stimulating the natural production of IGF-1 is that as its name suggests, insulin growth factor one, it is insulin-dependent in many ways.

但请记住，这些都是处方药，它们确实有自己的风险。刺激 IGF-1 自然产生的另一件事是，顾名思义，胰岛素生长因子一，它在很多方面都依赖于胰岛素。

If not for its secretion, then for its action at the hair follicle and stem cell.

如果不是因为它的分泌，那么就是因为它对毛囊和干细胞的作用。

So one of the things you really want to pay attention to is to avoid being insulin resistant, or rather you want to try to be insulin sensitive.

因此，您真正要注意的事情之一是避免产生胰岛素抵抗，或者更确切地说，您想尝试变得胰岛素敏感。

So if you're carrying a lot of excess body fat, if you're obese, or if you have type 2 diabetes, meaning you're insulin resistant, you're going to want to deal with that.

因此，如果您体内有大量多余脂肪，如果您肥胖，或者您患有 2 型糖尿病（意味着您有胰岛素抵抗），那么您将需要解决这些问题。

There are a number of prescription treatments to deal with that.

有许多处方疗法可以解决这个问题。

Nowadays, people are very excited about all the GLP-1 agonists, but in addition to that, regular cardiovascular exercise and resistance exercise, making sure that your body fat percentage is not in excess of where it needs to be.

如今，人们对所有 GLP-1 激动剂都非常兴奋，但除此之外，还要定期进行心血管锻炼和抗阻锻炼，以确保您的体脂百分比不超过所需的水平。

And everyone has a slightly different idea of where it needs to be, both cosmetically and for health, so that's a conversation between you and your doctor and you and you, frankly.

每个人对它需要在哪里的想法都略有不同，无论是为了美观还是为了健康，所以坦率地说，这是你和你的医生、你和你之间的对话。

But you want to avoid being insulin resistant, because being insulin resistant and being obese can indeed lead to hair loss.

但你要避免出现胰岛素抵抗，因为胰岛素抵抗和肥胖确实会导致脱发。

And there are many people out there who are not obese who nonetheless are experiencing hair thinning and hair loss because they are insulin resistant by way of reduced IGF-1 activity.

有许多人虽然并不肥胖，但却正在经历头发稀疏和脱发的情况，因为他们因 IGF-1 活性降低而产生胰岛素抵抗。

There are a few supplements, so these are over-the-counter supplements, such as myo-inositol, taken at dosages of about 900 milligrams before sleep, which by the way can also assist in sleep, or things like berberine or metformin, which are known to improve insulin sensitivity.

有一些补充剂，所以这些都是非处方补充剂，例如肌醇，睡前服用约 900 毫克的剂量，顺便说一句，它也可以帮助睡眠，或者像小檗碱或二甲双胍这样的东西，已知可以提高胰岛素敏感性。

Each and every one of these has its own profile of positive and negative effects.

其中每一项都有其自身的积极和消极影响。

The lowest number of side effects is associated with 900-milligram myo-inositol taken about 30 minutes before sleep, mostly because it can make people a little bit drowsy and it does aid sleep in some really great ways.

睡前约 30 分钟服用 900 毫克肌醇的副作用最少，主要是因为它会使人有点昏昏欲睡，而且确实以一些非常好的方式帮助睡眠。

But really, exercise and maintaining a healthy nutritional program are also going to be key.

但实际上，锻炼和保持健康的营养计划也将是关键。

You just can't discard those.

你就是不能丢弃那些。

Berberine, which is a substance made from tree bark, is sometimes called the poor man's metformin, metformin being the equally effective prescription version of berberine.

小檗碱是一种由树皮制成的物质，有时被称为穷人的二甲双胍，二甲双胍是小檗碱的同等有效的处方版本。

Or put differently, berberine is the non-prescription but equally effective version of metformin.

或者换句话说，小檗碱是二甲双胍的非处方但同样有效的版本。

Keep in mind that both berberine and metformin dramatically reduce blood sugar levels, and so if you're not going to take them with carbohydrates, it can lead to some feelings of discomfort.

请记住，小檗碱和二甲双胍都会显着降低血糖水平，因此如果您不打算将它们与碳水化合物一起服用，可能会导致一些不适的感觉。

That's why I'm not a fan of them.

这就是为什么我不是他们的粉丝。

But if your goal is to really improve insulin sensitivity, they are considered very potent tools on the list of things that can do that.

但如果您的目标是真正提高胰岛素敏感性，那么它们被认为是可以做到这一点的非常有效的工具。

The other thing that's really important for maintaining proper hair growth, this anagen phase, is that you need sufficient iron.

对于维持头发正常生长（即生长期），另一件事非常重要，那就是您需要足够的铁。

This is because iron and ferritin play a key role in the cell growth pathways that go from the stem cells to the stimulation of keratin within the hair itself.

这是因为铁和铁蛋白在从干细胞到刺激头发本身角蛋白的细胞生长途径中发挥着关键作用。

Don't have time to go into this pathway in a lot of detail, but you can have your blood levels of iron measured.

没有时间详细介绍这一途径，但您可以测量血液中的铁含量。

This turns out to be pretty important because you don't just want to start popping iron supplements because too much iron can be toxic.

事实证明，这一点非常重要，因为您不只是想开始服用铁补充剂，因为过多的铁可能有毒。

Too little means you're anemic.

太少意味着你贫血。

For women, the levels of iron that you want are somewhere between 25 and 100, and for men, somewhere between 30 and 150.

对于女性来说，您想要的铁含量在 25 到 100 之间，而对于男性来说，您想要的铁含量在 30 到 150 之间。

Fortunately, the tests or the blood tests for iron are usually a very inexpensive add to your current blood panel.

幸运的是，铁的测试或血液测试通常是对您当前的血液检查的一种非常便宜的补充。

So if you're going in for a blood panel for LDL, HDL, kind of typical things, or if you're doing the more elaborate hormone testing, which I do recommend people do if they can afford it or if their insurance covers it, do ask for an iron test as well.

因此，如果您要进行低密度脂蛋白、高密度脂蛋白等典型检查的血液检测，或者如果您正在进行更复杂的激素检测（我建议人们在负担得起或保险承保的情况下进行检测），也请要求进行铁检测。

And if your iron is low, you may need to supplement your iron.

如果您的铁含量较低，您可能需要补充铁质。

If your iron is too high, that's not good either.

如果你的铁太高，那也不好。

But iron plays a key role in the anagen phase of hair growth.

但铁在头发生长的生长期起着关键作用。

So you want to make sure you at least have sufficient iron, and if you don't, you want to make sure that you're getting it from nutrition and/or supplementation.

因此，您要确保至少有足够的铁，如果没有，您要确保从营养和/或补充剂中获取铁。

Okay, so earlier we were talking about dihydrotestosterone.

好的，之前我们讨论过二氢睾酮。

Dihydrotestosterone, just to jog your memory, is a form of testosterone that can bind the androgen receptor at five times the affinity of regular testosterone.

双氢睾酮，只是为了唤起你的记忆，是睾酮的一种形式，它可以结合雄激素受体，其亲和力是常规睾酮的五倍。

Both men and women have a lot of testosterone relative to estrogen.

相对于雌激素来说，男性和女性都有大量的睾酮。

It just so happens that men tend to have more testosterone than women do overall.

碰巧的是，男性总体上往往比女性拥有更多的睾丸激素。

But both men and women, as they age, convert more of the testosterone they have to dihydrotestosterone.

但随着年龄的增长，男性和女性都会将更多的睾酮转化为二氢睾酮。

And dihydrotestosterone does two things that are bad for hair maintenance and hair growth.

二氢睾酮有两件事对头发保养和头发生长不利。

First of all, it shortens the anagen phase, that growth phase.

首先，它缩短了生长期，即生长期。

So whatever hair is going to grow is going to occur over a shorter period of time.

因此，无论头发长出什么，都会在较短的时间内发生。

Second of all, because of the presence of androgen receptors on the stem cell niche area and around it, it actually miniaturizes the follicle and the stem cell niche.

其次，由于干细胞生态位区域及其周围存在雄激素受体，它实际上使卵泡和干细胞生态位微型化。

In other words, it makes the population of cells that give rise to more hair protein smaller and can eliminate it altogether.

换句话说，它使产生更多毛发蛋白的细胞群变小，并且可以将其完全消除。

And that is why anything that reduces 5-alpha reductase is going to reduce DHT, is going to maintain or extend the growth phase, the anagen phase of hair growth, and is going to offset or prevent some of the telogen phase, the pinching off and the removal of that stem cell niche.

这就是为什么任何减少 5-α 还原酶的物质都会减少 DHT，维持或延长生长期，即头发生长的毛发生长初期，并且会抵消或防止一些休止期、干细胞生态位的夹断和去除。

Now, one substance that we know can inhibit 5-alpha reductase, although it does it pretty weakly, is saw palmetto, which is an extract of the saw palmetto berry.

现在，我们知道一种可以抑制 5-α 还原酶的物质，尽管它的作用很弱，那就是锯棕榈，它是锯棕榈浆果的提取物。

To be honest, I don't know how this was initially discovered.

说实话，我不知道这个最初是怎么发现的。

If anyone knows, please put it in the show note captions.

如果有人知道，请把它放在节目注释标题中。

When I looked online, I found a bunch of conflicting stories about who was the first person to start extracting the extract of the saw palmetto berries, so I have no idea which one of those is true.

当我在网上查找时，我发现了一堆关于谁是第一个开始提取锯棕榈浆果提取物的人的相互矛盾的故事，所以我不知道哪一个是真实的。

Maybe somebody can tell me.

也许有人可以告诉我。

The good thing about saw palmetto treatment is that it is known to have very few, if any, side effects.

锯棕榈治疗的好处是，众所周知，它的副作用非常少（如果有的话）。

There might be some side effects in about 1% of people, but it's not associated with a lot of side effects.

大约 1% 的人可能会出现一些副作用，但不会产生很多副作用。

It's also known that when taken at about 300 milligrams per day, and here it doesn't have to be that strict, most of the studies that I explored involved taking anywhere from 200 to 500 milligrams of saw palmetto, but most of them focused on about 300 milligrams of saw palmetto per day, divided into two or three doses.

众所周知，当每天服用约 300 毫克时，这里不必那么严格，我探索的大多数研究都涉及服用 200 至 500 毫克锯棕榈，但其中大多数集中于每天约 300 毫克锯棕榈，分为两到三剂。

Why?

为什么？

Well, it has a relatively short half-life, meaning it's going to get cleared from the bloodstream, and more importantly, its biological action is going to be very short-lived.

嗯，它的半衰期相对较短，这意味着它会从血液中清除，更重要的是，它的生物作用将非常短暂。

So if you can get ahold of 50 or 100-milligram capsules or tablets of saw palmetto and divide those up Taking them in the morning, afternoon, and evening, or even just in the morning and evening to achieve a total of about 300 milligrams per day, that's going to very likely help you hold onto some of the hair that you would've otherwise lost, maybe even grow some new hair.

因此，如果你能拿到 50 或 100 毫克的锯棕榈胶囊或片剂，并将它们分成早上、下午和晚上服用，甚至只在早上和晚上服用，以达到每天约 300 毫克的总量，这很可能会帮助你保留一些本来会脱落的头发，甚至可能长出一些新头发。

And I say maybe give you some new hair growth because saw palmetto is not known to be a particularly robust treatment for the reversal of hair loss.

我说也许会给你一些新的头发生长，因为锯棕榈并不是已知的逆转脱发的特别有效的治疗方法。

It's known to have some effect, but it's generally taken in conjunction with a bunch of other things.

众所周知，它有一定的效果，但它通常与许多其他东西结合使用。

And so it's really hard to tease out just what amount of hair growth or prevention of hair loss is due to saw palmetto specifically, but I mention it here because the mechanism of action is logical and fairly well-known, which is this weak effect in reducing 5-alpha reductase and thereby reducing DHT.

因此，很难弄清楚锯棕榈到底能促进多少头发生长或防止脱发，但我在这里提到它是因为其作用机制是合乎逻辑的并且相当众所周知，这就是减少 5-α 还原酶从而减少 DHT 的微弱作用。

So again, because it has relatively low side effects, even though it's not super effective, and because it's fairly low cost and it's available over the counter, I felt it was important to include.

再说一次，因为它的副作用相对较低，尽管它不是超级有效，而且因为它的成本相当低并且可以在柜台上买到，所以我觉得包括在内很重要。

Now, as soon as people hear things like saw palmetto berry, they're probably also thinking, "Oh, boy.

现在，一旦人们听到锯棕榈浆果之类的东西，他们可能也会想，“哦，男孩。

Here come all the herbals." Now, keep in mind that there are some herbal compounds that have pretty robust biological effects.

所有的草药都来了。”现在，请记住，有些草药化合物具有相当强大的生物效应。

And we talked before in our optimizing testosterone episodes about things like tongkat ali and Fadogia agrestis, which taken in correct dosages and in the correct way can be pretty potent for increasing luteinizing hormone and free testosterone.

我们之前在优化睾酮水平中谈到过东革阿里和 Fadogia agrestis 之类的东西，以正确的剂量和正确的方式服用它们可以非常有效地增加黄体生成素和游离睾酮。

Not going to have huge effects.

不会产生巨大的影响。

It's not like taking exogenous anabolic steroids, but they can have real effects.

这不像服用外源性合成代谢类固醇，但它们可以产生真正的效果。

And so herbal compounds can be potent.

因此，草药化合物可能是有效的。

However, I do acknowledge that there's a vast market out there of herbal compounds and plant-based compounds that people are arguing, mostly the people who sell them are arguing, can increase hair growth.

然而，我确实承认，人们认为草药化合物和植物性化合物有一个广阔的市场，大多数销售者都认为它们可以促进头发生长。

And there are some decent studies of these things.

对这些事情有一些不错的研究。

The hard part about studying these herbal compounds and these plant-derived compounds for increasing hair growth is that they are often taken in combination with one another.

研究这些草药化合物和植物源性化合物促进头发生长的困难之处在于，它们经常相互结合使用。

In fact, most of the hair growth supplements that involve these herbal compounds and plant compounds include 5 or 10, sometimes even more things altogether, so teasing out which ones are effective and which dosages are effective is nearly impossible.

事实上，大多数涉及这些草药化合物和植物化合物的生发补充剂都包含 5 种或 10 种，有时甚至更多，因此要弄清楚哪些是有效的以及哪些剂量是有效的几乎是不可能的。

There are just too many variables.

变量太多了。

So you will hear, for instance, that green tea extract, reishi mushroom, pumpkin oil, zinc, curcumin, that all of these things can increase hair growth.

所以你会听说，例如，绿茶提取物、灵芝蘑菇、南瓜油、锌、姜黄素，所有这些东西都可以促进头发生长。

Perhaps the only thing on that list that makes logical sense with respect to the biochemistry is that curcumin is known to, in some people, be a potent inhibitor of 5-alpha reductase and DHT.

也许该列表中唯一在生物化学方面具有逻辑意义的事情是，姜黄素对某些人来说是 5-α 还原酶和 DHT 的有效抑制剂。

So much so that I can personally say, for me, I once took curcumin, turmeric it's also called, in high dosage.

以至于我个人可以说，对我来说，我曾经服用过高剂量的姜黄素，也称为姜黄。

This is about a gram to two-gram capsules, and I felt absolutely terrible.

这是大约一克到两克的胶囊，我感觉非常糟糕。

I mean, just dreadful.

我的意思是，太可怕了。

I don't care if it allowed me to keep my hair forever, I would rather lose all my hair three times over...

我不在乎它是否能让我永远保留头发，我宁愿把头发全部掉三遍……

Well, I guess that means it would've grown back.

嗯，我想这意味着它会长回来。

I'd rather lose all my hair, let's just put it that way, than ever take curcumin or turmeric in high dosages again.

我宁愿失去所有的头发，这么说吧，也不愿再次服用高剂量的姜黄素或姜黄。

And in saying that, I know that many people take turmeric and curcumin and really like its anti-inflammatory properties and don't experience any side effects.

说到这里，我知道很多人服用姜黄和姜黄素，并且非常喜欢它的抗炎特性，并且没有任何副作用。

I just happen to be particularly sensitive to curcumin by way of this DHT pathway, and I know this by way of blood work, so I'm never going near that stuff again.

我只是碰巧通过这种 DHT 途径对姜黄素特别敏感，而且我通过血液检查知道了这一点，所以我再也不会接近那些东西了。

That said, a lot of these herbal compounds and cocktails probably will have some minor, marginal, infinitesimally small, somewhere in that range, effect on maintaining hair growth or in stimulating new hair growth.

也就是说，许多这些草药化合物和鸡尾酒可能会对维持头发生长或刺激新头发生长产生一些微小的、边际的、无限小的影响，在这个范围内的某个地方。

It's just that there really aren't clinical studies to support any one of them, and that's why I singled out saw palmetto as one of the few for which the biochemical pathway of inhibiting 5-alpha reductase and the low incidence of side effects and the fact that many people have used it with some degree of success makes it a standalone, I wouldn't say recommendation, but a consideration.

只是确实没有临床研究支持其中任何一种，这就是为什么我选择锯棕榈作为少数几种具有抑制 5-α 还原酶的生化途径和低副作用发生率的药物之一，而且许多人使用它并取得一定程度的成功这一事实使其成为一种独立的药物，我不会说是推荐，而是一种考虑。

Another commonly discussed and used commercial compound for offsetting hair loss and stimulating hair growth is ketoconazole.

另一种经常讨论和使用的用于抵消脱发和刺激毛发生长的商业化合物是酮康唑。

Sometimes this is known as Nizoral, where Nizoral is the brand name of a shampoo.

有时这被称为 Nizoral，其中 Nizoral 是洗发水的品牌名称。

Ketoconazole is an antifungal that was initially developed to treat dandruff and severe psoriasis.

酮康唑是一种抗真菌药，最初是为了治疗头皮屑和严重牛皮癣而开发的。

So ketoconazole has been shown to be effective in increasing hair number.

因此，酮康唑已被证明可以有效增加头发数量。

It's also been shown to be effective in increasing hair diameter, which is somewhat surprising because one of the common side effects of ketoconazole is drying, thinning, and brittle hair.

它还被证明可以有效增加头发直径，这有点令人惊讶，因为酮康唑的常见副作用之一是头发干燥、稀疏和脆弱。

So what's going on there is a little unclear.

所以那里发生的事情有点不清楚。

We'll return to that in a moment.

我们稍后会回到这个话题。

The mechanism of action for ketoconazole is pretty interesting.

酮康唑的作用机制非常有趣。

Remember earlier we were talking about the sebaceous gland and the production of sebum, that oily stuff whose very name seems to evoke disgust in certain people?

还记得之前我们谈论过皮脂腺和皮脂的产生吗？皮脂是一种油性物质，其名字似乎会引起某些人的厌恶？

Well, ketoconazole can disrupt some of the fungal growth that, frankly, we all have on our scalp all the time.

坦白说，酮康唑可以破坏我们头皮上一直存在的一些真菌生长。

I know this is a surprise to many of you, but you are constantly bombarded with viruses, bacteria, and funguses all the time.

我知道这对你们许多人来说是一个惊喜，但你们一直在不断地受到病毒、细菌和真菌的轰炸。

But we manage to battle those off with our immune system, either by physical barriers such as an oil barrier, like the sebum, or through antimicrobial action, so chemical approaches, our immune system, the sebum, et cetera.

但我们设法用我们的免疫系统来对抗这些细菌，要么通过物理屏障，如油脂屏障，如皮脂，要么通过抗菌作用，如化学方法、我们的免疫系统、皮脂等等。

Ketoconazole acts as an antifungal that in some way seems to reinforce the properties of sebum at keeping out other fungal infections.

酮康唑作为一种抗真菌剂，在某种程度上似乎可以增强皮脂的特性，以防止其他真菌感染。

And the net effect, at least as far as we know, is a mild reduction in DHT.

至少据我们所知，最终的效果是双氢睾酮的轻微减少。

Now, exactly how this happens isn't really clear.

现在，这究竟是如何发生的还不清楚。

What is clear is that the use of ketoconazole shampoos two to four times per week with a scalp contact time of about three to five minutes has been shown to give about an 80% response rate of maintaining hair that would otherwise be lost.

显而易见的是，每周使用酮康唑洗发水 2 至 4 次，接触头皮时间约 3 至 5 分钟，已被证明可以保持头发的有效率约 80%，否则头发可能会脱落。

So that's pretty dramatic, 80%.

所以这是相当戏剧性的，80%。

What is less clear is whether or not ketoconazole shampoo can actually stimulate new hair growth.

不太清楚的是酮康唑洗发水是否真的可以刺激新头发的生长。

But as you're probably starting to realize, this is always a bit of a tough thing to disentangle, maintenance of hair that you would've lost versus new hair growth.

但正如您可能开始意识到的那样，维护已失去的头发与新头发的生长总是有点困难。

Certainly, that's an easy thing to disambiguate if you have a patch of scalp where there is absolutely no hair, these so-called dead zones that you can resurrect With certain treatments.

当然，如果你有一块完全没有头发的头皮，那么这是很容易消除歧义的，这些所谓的死区可以通过某些治疗来复活。

But what about areas of your scalp where hair is thinning?

但是头皮上头发稀疏的区域又如何呢？

So for instance, on the top of your head, this is where many women will first experience pattern hair loss.

例如，在头顶，这是许多女性首先经历脱发的地方。

Alopecia is right at their midline.

脱发就在他们的中线。

Especially if they have a part right there, they'll start to notice that under very bright light, fluorescent lights in particular, they'll notice a thinning of their hair there or in the forehead region.

特别是如果他们在那里有一个部位，他们会开始注意到，在非常亮的光线下，特别是荧光灯下，他们会注意到那里或前额区域的头发稀疏。

They'll start using ketoconazole shampoo.

他们将开始使用酮康唑洗发水。

Again, the typical recommendation is two to four times per week with a scalp contact time of three to five minutes and really rubbing it in and then rinsing it out.

同样，典型的建议是每周两到四次，接触头皮的时间为三到五分钟，真正揉搓，然后冲洗掉。

You don't need to be super vigorous, but you want to make sure that it gets down into the follicle and around the follicles, not just sitting on top of the hair, which is going to be especially important for people who have long hair to really massage it in.

你不需要非常有活力，但你要确保它深入毛囊和毛囊周围，而不仅仅是坐在头发上，这对于长发的人来说尤其重要，需要真正按摩头发。

Well, they will experience a growth of hair in that particular region that almost certainly were due to miniaturization of the hair follicle and reduction of the total population of stem cells in that follicle, as opposed to complete loss of the stem cell population.

嗯，他们会在那个特定区域经历毛发的生长，这几乎肯定是由于毛囊的小型化和毛囊中干细胞总数的减少，而不是干细胞群的完全丧失。

The reason we say this is that there's no reason to think that ketoconazole can actually stimulate IGF-1 or activate growth itself.

我们之所以这么说，是因为没有理由认为酮康唑实际上可以刺激 IGF-1 或激活生长本身。

It's probably offsetting some of the reductions in the anagen phase and some of the exacerbation of the telogen phase.

它可能抵消了生长期阶段的一些减少和休止期阶段的一些恶化。

Now, if you decide to use ketoconazole as an approach to offsetting hair loss, it's very important that you get a hold of a shampoo that's at least 2% concentration of ketoconazole.

现在，如果您决定使用酮康唑作为抵消脱发的方法，那么使用酮康唑浓度至少为 2% 的洗发水非常重要。

This is important because a lot of the ones that are available out there, especially online, are going to be 1% or lower.

这很重要，因为很多可用的，尤其是在线的，价格都是 1% 或更低。

So you want to try and obtain a ketoconazole shampoo of 2% or higher concentration of ketoconazole because it has other things in it, of course.

所以你想尝试使用2%或更高浓度的酮康唑洗发水，因为它当然含有其他物质。

I should mention that there are occasional side effects with ketoconazole.

我应该提到酮康唑偶尔会出现副作用。

The rates of side effects from the meta-analyses and reviews that I read were somewhere between one and 8% of people will experience some side effects, but those side effects tend to be pretty mild.

我读过的荟萃分析和评论显示，副作用发生率在 1% 到 8% 之间，有 1% 到 8% 的人会出现一些副作用，但这些副作用往往相当轻微。

Things like irritation of the scalp, things like thinning and brittleness of the hair that sometimes can be offset by using shampoos that contain things like biotin.

诸如头皮刺激、头发稀疏和脆弱之类的问题有时可以通过使用含有生物素等物质的洗发水来抵消。

I know many people are probably curious about biotin, which is a protein that can be incorporated into the keratin.

我知道很多人可能对生物素感到好奇，生物素是一种可以融入角蛋白的蛋白质。

Whether or not different biotin-enriched shampoos can really enhance the total amount of biotin that gets incorporated into the hair isn't clear, but it is clear that having sufficient biotin around is important.

不同的富含生物素的洗发水是否真的能增加头发中生物素的总量尚不清楚，但很明显，拥有足够的生物素很重要。

So if you get a little bit extra from your shampoo, you can imagine how that would, quote-unquote, "tap off" the amount of biotin in that hair.

因此，如果您从洗发水中获得一点额外的生物素，您可以想象这将如何（引用不引用）“消耗”头发中的生物素量。

And there are people out there saying that biotin-enriched shampoos have done wonders for them.

有人说富含生物素的洗发水给他们带来了奇迹。

Who knows?

谁知道？

I'm not going to dispute their experience.

我不会质疑他们的经历。

So if you're going to use ketoconazole, keep in mind that the more typical brand names that are out there, you know which ones they are, oftentimes don't have 2%, or if they do have 2%, they can be very drying and lead to brittle hair.

因此，如果您打算使用酮康唑，请记住，那些比较典型的品牌名称，您知道它们是什么，通常没有 2%，或者如果确实有 2%，它们可能会非常干燥并导致头发脆弱。

There are newer and now, fortunately, a greater variety of ketoconazole-containing shampoos.

幸运的是，现在有更多种类的含酮康唑洗发水。

We, as a podcast, and I don't have any affiliation to any of these, but I will provide links to a couple of the more prominent ones that are known to have 2% concentration of ketoconazole, as well as some other things in them known to offset some of that dryness and brittleness that ketoconazole shampoos can trigger.

作为一个播客，我们和我与这些产品没有任何关系，但我将提供一些已知含有 2% 浓度酮康唑的更知名产品的链接，以及其中的一些其他成分，这些成分已知可以抵消酮康唑洗发水可能引发的干燥和脆性。

So by now, I think it will be abundantly clear why inhibiting 5-alpha reductase and thereby reducing DHT should increase hair growth because of the negative impact that DHT has on the hair follicle.

因此，到目前为止，我认为抑制 5-α 还原酶从而减少 DHT 会促进头发生长的原因已经非常清楚了，因为 DHT 对毛囊有负面影响。

The major player in this whole story around inhibiting 5-alpha reductase and reducing DHT to maintain or increase hair growth is going to be finasteride and its close cousin, dutasteride.

在抑制 5-α 还原酶和减少 DHT 以维持或促进头发生长的整个故事中，主要角色将是非那雄胺及其近亲度他雄胺。

Finasteride is effective in reducing DHT because of its actions in reducing the type two isoenzyme or isoform of 5-alpha reductase.

非那雄胺可有效减少 DHT，因为它具有减少 5-α 还原酶的二型同工酶或同工型的作用。

It turns out there's three different isoforms or what are sometimes called isoenzymes of 5-alpha reductase.

事实证明，5-α 还原酶存在三种不同的异构体，或者有时称为同工酶。

This is getting pretty far down in the weeds.

这已经离杂草很远了。

What I think most of you just need to know is that finasteride reduces DHT.

我想你们大多数人只需要知道非那雄胺可以减少 DHT。

That's the net product of finasteride.

这就是非那雄胺的净产物。

And in doing so, it can increase hair count by as much as 20%.

这样做可以使头发数量增加多达 20%。

Pretty remarkable if you think about it.

如果你仔细想想的话，这是非常了不起的。

In addition, finasteride treatment done properly, which we'll define in a moment, can reduce hair loss in 90% of all people that take it.

此外，正确进行非那雄胺治疗（我们稍后将对其进行定义）可以减少 90% 服用该药物的人的脱发。

That is near staggering.

这几乎是令人震惊的。

There aren't many pharmaceuticals out there that have that kind of efficacy.

具有这种功效的药物并不多。

Really dramatic.

真是戏剧性。

And in addition, it's known to increase hair thickness by about 20% to 30% overall.

此外，众所周知，它可以使头发整体厚度增加约 20% 至 30%。

So not just create new growth of hairs and thicker hairs, but whatever hair you do happen to have on your head, it can further thicken those.

因此，不仅会产生新的头发生长和更浓密的头发，而且无论您头上有什么头发，它都会使这些头发进一步变厚。

So the finasteride story is one, I think, of general success.

因此，我认为非那雄胺的故事是普遍成功的故事之一。

It really seems to improve hair growth and help you hold on to the hair that you have.

它似乎确实可以改善头发生长并帮助您保持现有的头发。

The issue with finasteride is twofold.

非那雄胺的问题是双重的。

First of all, it is known to have some pretty significant side effects if it's not dosed properly and in particular populations of people.

首先，众所周知，如果剂量不当，尤其是特定人群，它会产生一些相当严重的副作用。

And this is because there is a wide variation in the amount of the different isoenzymes that people make.

这是因为人们产生的不同同工酶的数量存在很大差异。

So this is why I brought up the isoenzymes earlier.

这就是我之前提到同工酶的原因。

Some people make more of isoenzyme one and three.

有些人会产生更多的同工酶一和三。

Some people make more of isoenzyme two and three, and every variation thereof.

有些人制造更多的同工酶二号和三号及其各种变体。

So when people take finasteride, some people are very strong responders, and they achieve really effective hair regrowth and maintenance of hair.

所以当人们服用非那雄胺时，有些人的反应非常强烈，他们实现了真正有效的头发再生和头发保养。

Other people, less effective, although still pretty impressive.

其他人虽然效率较低，但仍然令人印象深刻。

But the catalog of side effects that people experience at a given dose varies widely.

但人们在给定剂量下所经历的副作用目录差异很大。

So there's a lot of trial and error that has to take place.

因此，必须进行大量的试验和错误。

Also should point out that finasteride comes in two major forms.

还应该指出的是，非那雄胺有两种主要形式。

There's an oral form and there's a topical form.

有口头形式和局部形式。

So this is not unlike our discussion of minoxidil earlier.

所以这与我们之前讨论的米诺地尔没有什么不同。

Topical finasteride is typically taken in 1% solution or ointment and rubbed into the head.

外用非那雄胺通常以 1% 的溶液或软膏形式服用，并擦入头部。

Sometimes it's now also incorporated into shampoos, but typically it's put into a solution that people rub into their head, and it is thought that the 1% solutions are equivalent to one milligram of systemic finasteride.

有时它现在也被加入到洗发水中，但通常它被放入人们擦在头上的溶液中，人们认为 1% 的溶液相当于一毫克全身非那雄胺。

Now we need to take a step back and ask why was finasteride developed in the first place?

现在我们需要退一步问，为什么要开发非那雄胺？

Well, finasteride as a fairly potent 5-alpha reductase inhibitor It's great at lowering DHT.

嗯，非那雄胺作为一种相当有效的 5-α 还原酶抑制剂，在降低 DHT 方面非常有效。

It was developed for treatment of prostate enlargement and various issues of the prostate that are associated with elevated DHT that occurs with age.

它被开发用于治疗前列腺肥大以及与随年龄增长而出现的 DHT 升高相关的各种前列腺问题。

The topical finasterides were designed with the hope that the finasteride would make it into the hair follicle and would inhibit DHT there and allow for more growth of the hair, which apparently it does, but not make it into the systemic circulation, or at least not at concentrations sufficient enough to cause as many side effects as with the oral dosing.

外用非那雄胺的设计初衷是希望非那雄胺能够进入毛囊并抑制那里的双氢睾酮（DHT）并允许头发更多生长（显然确实如此），但不会进入全身循环，或者至少浓度不足以引起与口服给药一样多的副作用。

Now, the problem is, it does make it into systemic circulation.

现在的问题是，它确实进入了系统循环。

The issue is also that topical application of finasteride is harder to dose than oral finasteride.

问题还在于，局部应用非那雄胺比口服非那雄胺更难给药。

I'm not saying you should be taking oral rather than topical finasteride, but keep in mind that the dosages of finasteride that have been shown to be effective for inducing hair growth cover an enormous range, so as low as 0.01 milligrams per day and as high as five milligrams per day, which is a just staggering range.

我并不是说你应该口服而不是外用非那雄胺，但请记住，已证明可有效促进毛发生长的非那雄胺剂量范围很广，低至每天 0.01 毫克，高至每天 5 毫克，这是一个令人震惊的范围。

Now, in trying to simplify the problem of how much finasteride to take, either by way of oral tablet or by way of topical solution, we can get a bit of leverage on this by thinking about how much DHT reduction occurs as a function of dose.

现在，在试图简化非那雄胺服用量的问题时，无论是通过口服片剂还是通过局部溶液的方式，我们可以通过考虑作为剂量函数的 DHT 减少量来获得一些杠杆作用。

And there, finasteride shows this really interesting what's called logarithmic distribution.

在那里，非那雄胺展示了这种非常有趣的对数分布。

What it means is that for a dosage of 0.01 milligrams of finasteride, you're going to achieve approximately 50% reduction in DHT, and that's systemic DHT.

这意味着，服用 0.01 毫克非那雄胺，您的 DHT 就会减少约 50%，这是全身性的 DHT。

So this is a blood draw measuring your DHT, then taking 0.01 milligrams of finasteride, again, 0.01, a very low dose of finasteride, for a period of a couple of weeks, measure people's DHT in their blood again, and you see that it's reduced by 50%.

这是抽血测量您的 DHT，然后再次服用 0.01 毫克非那雄胺，0.01 毫克，非常低剂量的非那雄胺，持续几周，再次测量人们血液中的 DHT，您会发现它减少了 50%。

However, at increasing dosages of 0.2 milligrams, one milligrams, five milligrams of oral finasteride per day over the same period of time, the increase, or I should say the reduction in dihydrotestosterone doesn't increase linearly.

然而，在同一时间段内每天口服非那雄胺剂量增加0.2毫克、1毫克、5毫克时，二氢睾酮的增加，或者我应该说，二氢睾酮的减少并不是线性增加的。

It's not that you go from 50% to 60% to 75% to 100% with each increasing dose.

并不是说每次增加剂量就从 50% 到 60%、75% 到 100%。

It tapers off.

它逐渐减弱。

It kind of flattens out.

它有点变平了。

It tends to increase a little bit, but it's sort of a gradual slope increasing as you head from 0.2 milligrams out to five milligrams.

它往往会增加一点，但当你从 0.2 毫克增加到 5 毫克时，它会逐渐增加。

So what this means is that given that reducing DHT can cause various side effects, sexual side effects, reductions in either sexual function or sexual drive, as well as overall drive and motivation, sometimes even some depressive symptoms that everything points to taking the lowest effective dose of finasteride and starting with a very low dose of finasteride because low doses of finasteride, even at that 0.01 milligrams taken orally daily, are already leading to a 50% reduction in dihydrotestosterone and thereby taken for a long enough period of time should offset hair loss and stimulate hair growth.

因此，这意味着，考虑到减少 DHT 可能会导致各种副作用、性副作用、性功能或性欲下降以及整体动力和动机，有时甚至是一些抑郁症状，一切都表明服用最低有效剂量的非那雄胺，并从非常低剂量的非那雄胺开始，因为低剂量的非那雄胺，即使每天口服 0.01 毫克，已经导致双氢睾酮减少 50%，从而服用足够长的时间应该可以抵消脱发并刺激头发生长。

One of the problems, however, is that people will start taking finasteride at a low dose, 0.1 milligrams or 0.2 milligrams, maybe even 0.01 milligrams, and there will be a reduction in their DHT.

然而，问题之一是，人们开始服用低剂量的非那雄胺（0.1 毫克或 0.2 毫克，甚至可能是 0.01 毫克），他们的 DHT 就会减少。

But because of the long duration of that anagen phase, they don't see a lot of change in hair growth in the first month or even two months.

但由于生长期持续时间较长，他们在第一个月甚至两个月内看不到头发生长的太大变化。

And so what they end up doing is increasing their dosage, and then they start to see hair growth, but then they start to experience more side effects.

所以他们最终要做的就是增加剂量，然后他们开始看到头发生长，但随后他们开始经历更多副作用。

Now, the side effects of oral finasteride are serious enough and common enough in people that take finasteride that the topical solutions were developed.

现在，口服非那雄胺的副作用在服用非那雄胺的人中足够严重和普遍，因此开发了局部解决方案。

But there too, one needs to exercise caution because if we are going to translate between topical finasteride and oral finasteride with the understanding that topical finasteride can actually make it into the systemic circulation, we need to look at what's been shown in clinical studies, which is that, for instance, taking one milliliter of 0.25% finasteride applied to the scalp, this is a very typical recommendation, translates to the same thing that would be achieved with 2.5 milligrams of oral finasteride.

但是，人们也需要谨慎行事，因为如果我们要在外用非那雄胺和口服非那雄胺之间进行转换，并了解外用非那雄胺实际上可以进入体循环，我们需要看看临床研究中显示的内容，例如，将 1 毫升 0.25% 非那雄胺涂抹在头皮上，这是一个非常典型的建议，转化为使用 2.5 毫克非那雄胺所达到的效果是相同的。口服非那雄胺。

And when I say translates to the same thing, what I mean is it leads to the same concentrations in the blood.

当我说翻译为同一件事时，我的意思是它会导致血液中的浓度相同。

Now, consider that 0.2 milligrams, 0.2 milligrams of finasteride in the blood is known to be effective in generating new hair growth and maintaining hair that one already has when they start the treatment.

现在，考虑一下血液中 0.2 毫克、0.2 毫克的非那雄胺，已知可有效产生新的毛发生长并维持开始治疗时已有的毛发。

So if you think that the topical finasterides are actually creating lower overall systemic concentrations of finasteride, that is not necessarily the case.

因此，如果您认为外用非那雄胺实际上会降低非那雄胺的整体全身浓度，那么情况不一定如此。

Again, one milliliter of topical finasteride at 0.25% leads to a 2.5-milligram concentration in the blood when the effective dose within the bloodstream by taking it orally as a pill is 0.2 milligrams.

同样，当口服药丸在血液中的有效剂量为 0.2 毫克时，1 毫升 0.25% 的外用非那雄胺在血液中的浓度为 2.5 毫克。

That might not seem like a big deal to you, although it is a big deal, right?

这对你来说可能不是什么大不了的事，尽管它是一件大事，对吧？

We're talking 2.5 milligrams versus 0.2.

我们谈论的是 2.5 毫克与 0.2 毫克。

But it is a huge deal when you consider that the side effects of finasteride increase as you increase the concentration of finasteride in the bloodstream.

但当你考虑到非那雄胺的副作用随着血液中非那雄胺浓度的增加而增加时，这就很重要了。

So where does this leave us?

那么这会给我们带来什么影响呢？

Should people who are interested in taking finasteride take the oral form at low dose or take the topical form and simply try and apply it less often or guess at what their systemic concentration of finasteride is?

对服用非那雄胺感兴趣的人应该服用低剂量的口服形式还是服用外用形式并简单地尝试减少使用次数或猜测他们的非那雄胺的全身浓度是多少？

Well, it's going to vary from person to person.

嗯，这会因人而异。

Some people are very sensitive to finasteride and not in the good sense.

有些人对非那雄胺非常敏感，但不是很好。

The side effects just really show up quickly, and they tend to be dramatic.

副作用确实很快就会显现出来，而且往往是戏剧性的。

Other people, not so much.

其他人则不然。

The dosage recommendations that I was able to arrive at based on the clinical studies and frankly, in discussion with some doctors who prescribe finasteride, were the following: 0.5 milligrams to one milligram of finasteride as a tablet per day seems to be an effective and pretty safe starting place for most people.

坦率地说，在与一些开非那雄胺处方的医生讨论后，我根据临床研究得出的剂量建议如下：每天 0.5 毫克到 1 毫克非那雄胺片剂对于大多数人来说似乎是一个有效且相当安全的起始位置。

Now, some people will find that even that 0.5-milligram dosage is just going to cause side effects that are not going to work for them, and they're going to either have to reduce their dosage of finasteride or move to the topical, or maybe cease taking finasteride altogether.

现在，有些人会发现，即使 0.5 毫克的剂量也会产生对他们不起作用的副作用，他们要么必须减少非那雄胺的剂量，要么转向局部用药，或者可能完全停止服用非那雄胺。

But for many people out there, that's going to be pretty well-tolerated.

但对于很多人来说，这将是可以很好忍受的。

The key thing here is that one is going to have to wait some period of time to see whether or not any hair growth occurs.

这里的关键是，人们必须等待一段时间才能看到头发是否生长。

It is a naive and frankly, a foolish approach based on what we know about the duration of that anagen phase of the hair to do one of these treatments, wait a week or two, and then decide to up your dose.

根据我们对头发生长期持续时间的了解，进行其中一种治疗，等待一两周，然后决定增加剂量，这是一种天真而坦率的愚蠢方法。

Now, it is not foolish to reduce your dose if you're experiencing bad side effects.

现在，如果您出现严重的副作用，减少剂量并不是愚蠢的。

But to simply increase your dose because you're not getting results quickly enough, that's not going to be the best approach.

但因为不能足够快地获得结果而简单地增加剂量，这并不是最好的方法。

I really encourage people who are going to explore the finasteride route to think of this as a long-term project and to really ratchet up slowly, if at all, starting initially with a low dose taken for a long period of time, maybe even as long as 25 weeks before considering going up any further.

我真心鼓励那些打算探索非那雄胺路线的人将其视为一个长期项目，并真正缓慢地逐步增加剂量（如果有的话），首先从低剂量开始服用很长一段时间，甚至可能长达 25 周，然后再考虑进一步增加剂量。

Certainly, as I mentioned before, if you need to go down further, that's not going to be a problem, at least not in terms of reducing side effects.

当然，正如我之前提到的，如果你需要进一步降低，那不会成为问题，至少在减少副作用方面不会。

I mean, you're not going to get additional hair growth, but you're certainly not going to increase your side effects if you reduce your dose.

我的意思是，你不会获得额外的头发生长，但如果你减少剂量，你肯定不会增加副作用。

However, I will talk a little bit later about post-finasteride syndrome, which is something that's getting increasing attention nowadays.

不过，我稍后会谈谈非那雄胺后综合症，这是当今越来越受到关注的问题。

That's something that occurs after people have taken finasteride for an extended period of time.

这是人们长期服用非那雄胺后发生的事情。

Now, some of you have perhaps heard, and I'll just tell you right here, that the topical forms of finasteride are associated with far less side effects.

现在，你们中的一些人可能已经听说过，我就在这里告诉你们，非那雄胺的外用形式的副作用要少得多。

Now, that might come as surprising given that topical application of finasteride can lead to systemic distribution of finasteride.

现在，考虑到局部应用非那雄胺可能导致非那雄胺的全身分布，这可能会令人惊讶。

But the numbers that are out there right now, it's that topical finasteride is associated with 30% to 50% fewer side effects or 30% to 50% less severe side effects than oral finasteride.

但目前的数据显示，与口服非那雄胺相比，外用非那雄胺的副作用减少了 30% 至 50%，严重副作用减少了 30% 至 50%。

Now, there are several things probably responsible for that.

现在，可能有几个原因造成了这种情况。

One is that people tend to ratchet up their dose of oral finasteride pretty quickly.

一是人们倾向于很快增加口服非那雄胺的剂量。

But keep in mind that the effective dose of finasteride in the blood is 0.2 milligrams.

但请记住，血液中非那雄胺的有效剂量为 0.2 毫克。

Now earlier I said the typical topical finasteride solutions are 0.25%.

前面我说过典型的外用非那雄胺溶液是 0.25%。

People are taking 1 mil of it, that equates to 2.5 milligrams, and so it seems like a massive overdosing.

人们服用了 100 万，相当于 2.5 毫克，所以这似乎是过量服用。

Ah, but here's the discrepancy, and here's where we can arrive at some reasonable recommendations.

啊，但这就是差异，我们可以在这里得出一些合理的建议。

If you decide that finasteride's right for you, you get a prescription, I would hope that you're monitoring your DHT levels and other hormone levels.

如果您认为非那雄胺适合您，您会得到处方，我希望您正在监测您的 DHT 水平和其他激素水平。

That would be ideal in working with a doctor, please.

请与医生合作是理想的选择。

0.5 milligrams to 1 milligram per day of oral finasteride seems to be the best starting place.

每天 0.5 毫克至 1 毫克口服非那雄胺似乎是最好的起点。

For topical finasteride, it's going to be that 1 milliliter of 0.25% that we talked about earlier, but that's taken only one time per week.

对于外用非那雄胺，我们之前提到过，剂量为 1 毫升 0.25%，但每周只使用一次。

And you can fully expect that right after the application, you will have higher levels of finasteride in your bloodstream, and therefore lower levels of DHT, and that that will alter across the week.

您完全可以预料到，在使用后，您的血液中非那雄胺的含量将会升高，因此 DHT 的含量也会降低，并且这种情况会在一周内发生变化。

Most people are not going to be able to measure their DHT on a day-by-day or even weekly basis.

大多数人无法每天甚至每周测量他们的 DHT。

It's just too expensive and labor-intensive.

它太昂贵且劳动密集型。

But I think those dosing regimens ought to get people into more or less the same category of optimizing hair maintenance and hair growth while minimizing finasteride side effects.

但我认为这些剂量方案应该让人们或多或少地进入优化头发保养和头发生长的同一类别，同时最大限度地减少非那雄胺的副作用。

One point about finasteride taken either alone or in combination is that in recent years, really in the last five or so years, there's been increasing discussion about so-called post-finasteride syndrome.

关于单独或联合服用非那雄胺的一点是，近年来，实际上是在过去五年左右，关于所谓的后非那雄胺综合症的讨论越来越多。

Now, post-finasteride syndrome is indeed a new phenomenon in the sense that finasteride has been prescribed for a very long period of time for treatment of the prostate at dosages of about 5 milligrams per day.

现在，非那雄胺后综合症确实是一种新现象，因为在很长一段时间内，非那雄胺以每天约 5 毫克的剂量用于治疗前列腺。

That's a very high dose.

这是一个非常高的剂量。

Sometimes lower, but as high as 5 milligrams per day.

有时较低，但最高可达每天 5 毫克。

And for many years, there was no discussion about this post-finasteride syndrome.

多年来，没有人讨论过这种后非那雄胺综合症。

What is post-finasteride syndrome?

什么是非那雄胺后综合症？

Post-finasteride syndrome is when, typically it's males, this is where it's been described, will take finasteride at any range of dosages from 1 milligram to 5 milligrams per day.

非那雄胺后综合症是指，通常是男性，这就是它所描述的，每天服用非那雄胺的任何剂量范围，从 1 毫克到 5 毫克。

They're either doing this for prostate or more likely they're doing it to offset hair loss and increase hair growth.

他们这样做要么是为了治疗前列腺，要么更有可能是为了抵消脱发并促进头发生长。

And then they stop taking finasteride for whatever reason, financial, or it wasn't working for them, or the side effects were not to their liking, and they start to experience some very severe what can only be called syndrome effects, such as very reduced libido, very reduced erectile function, very reduced mood to the point of depression, even suicidal depression.

然后他们出于某种原因停止服用非那雄胺，比如经济原因，或者它对他们不起作用，或者副作用不符合他们的喜好，他们开始经历一些非常严重的只能称为综合症的影响，例如性欲非常低下，勃起功能非常低下，情绪非常低落到抑郁的程度，甚至自杀抑郁症。

So this is pretty scary stuff, especially since it's occurring at an age when most of these things are not typically occurring in males.

所以这是非常可怕的事情，特别是因为它发生在大多数这些事情通常不会发生在男性身上的年龄。

They can occur, but they're not typical of younger males in their 20s and 30s and early 40s.

它们可能会发生，但在 20 多岁、30 多岁和 40 岁出头的年轻男性中并不常见。

So we have to ask ourselves, what's going on here?

所以我们必须问自己，这是怎么回事？

After all, people have taken finasteride for the prostate at fairly high dosages without this post-finasteride syndrome when they've stopped.

毕竟，人们服用相当高剂量的非那雄胺来治疗前列腺，停药后不会出现非那雄胺后综合症。

Now these young males are taking finasteride, they're coming off finasteride, and they're getting this very severe, very debilitating post-finasteride syndrome.

现在，这些年轻男性正在服用非那雄胺，他们正在停止服用非那雄胺，他们正在患上这种非常严重、非常虚弱的非那雄胺后综合症。

This has become a kind of hot topic, enough so that medical doctors who have been prescribing finasteride for a very long time have been forced to address this.

这已经成为一个热门话题，足以让长期开非那雄胺处方的医生被迫解决这个问题。

I think at first they were sort of perplexed and thought, "I don't know, this might be psychosomatic," whatever that means.

我想一开始他们有点困惑，想，“我不知道，这可能是心身问题”，不管这意味着什么。

I mean, as a neuroscientist who works on mind-body connection, we know that nothing is truly psychosomatic.

我的意思是，作为一名研究身心联系的神经科学家，我们知道没有什么是真正的身心联系。

Everything is of the mind and body.

一切都是心灵和身体的。

But the point is that enough medical attention has been placed on post-finasteride syndrome and trying to unravel exactly what that is, where there are now a few general conclusions about what might be going on.

但关键是，人们已经对非那雄胺后综合症给予了足够的医学关注，并试图弄清楚到底是什么，现在对于可能发生的情况有一些一般性的结论。

First of all, it seems that younger males taking finasteride, in particular at high dosages to improve hair growth or offset hair loss, seems to be one of the key variables.

首先，年轻男性服用非那雄胺，特别是高剂量服用非那雄胺以促进头发生长或抵消脱发，似乎是关键变量之一。

We're not seeing this post-finasteride syndrome as much in older males.

我们在老年男性中很少看到这种非那雄胺后综合症。

In fact, it seems to occur more in males in their 20s and 30s than males in their 40s and older.

事实上，20 多岁和 30 多岁的男性似乎比 40 多岁及以上的男性更容易发生这种情况。

So that's one thing, and it may relate to the ways in which dihydrotestosterone, we know, has a very key role in early embryonic development.

所以这是一回事，而且我们知道，它可能与二氢睾酮在早期胚胎发育中发挥非常关键的作用有关。

It's actually what's responsible for the male genitalia.

它实际上负责男性生殖器。

It's also responsible for certain things in female development, but mainly in utero, it's responsible for male development and development of the penis in particular.

它还负责女性发育中的某些事情，但主要是在子宫内，它负责男性发育，特别是阴茎的发育。

And then around the time of puberty, dihydrotestosterone acts again in what's called its activating effects To further increase growth of the genitalia, increase the musculature, bone growth, et cetera, and increase libido and a number of other things.

然后在青春期左右，二氢睾酮再次发挥所谓的激活作用，进一步促进生殖器的生长，增加肌肉组织、骨骼生长等，并增加性欲和许多其他方面。

It's probably also involved in the activation of puberty.

它可能也与青春期的激活有关。

It's certainly not the only hormone involved in the activation of male puberty, but it's certainly one of the key players.

它当然不是参与男性青春期激活的唯一激素，但它肯定是关键角色之一。

So dihydrotestosterone has these known early roles in embryonic development and in puberty, but what post-finasteride syndrome seems to indicate is that dihydrotestosterone is likely having further effects on male maturation, in particular maturation of the hypothalamus and areas of the brain that continue well into one's 20s and maybe even one's 30s.

因此，双氢睾酮在胚胎发育和青春期具有这些已知的早期作用，但非那雄胺后综合征似乎表明，二氢睾酮可能对男性成熟产生进一步影响，特别是下丘脑和大脑区域的成熟，这种影响会持续到 20 多岁，甚至可能持续到 30 多岁。

And here I just want everyone to keep in mind that we tend to think about development as childhood, teenage years, young adulthood, adulthood, but really development never stops.

在这里，我只是想让大家记住，我们倾向于将发展视为童年、青少年、青年时期、成年，但真正的发展永远不会停止。

Development is something that starts at conception and birth, of course, and then extends all the way out until the point when we die.

当然，发展是从受孕和出生开始，然后一直延伸到我们死亡的那一刻。

So even if we live to be in our late 90s or achieve 100 years of age, development is occurring that entire time, and these different hormones, such as dihydrotestosterone, are having different impact across the lifespan and in different ways across the lifespan.

因此，即使我们活到 90 多岁或达到 100 岁，发育也在整个过程中发生，而这些不同的激素，例如二氢睾酮，在整个生命周期中以不同的方式产生不同的影响。

So there isn't a clear conclusion about what post-finasteride syndrome is really all about, but it points to the fact that DHT is likely to be involved in development of the brain and the brain to genital axis, I mention that because so many of the side effects that are associated with this post-finasteride syndrome seem to center on sexual side effects, although there are also the depressive side effects.

因此，关于非那雄胺后综合症的真正含义还没有一个明确的结论，但它指出了这样一个事实，即双氢睾酮很可能参与大脑和大脑到生殖轴的发育，我提到这一点是因为与这种后非那雄胺综合症相关的许多副作用似乎集中在性方面的副作用，尽管也有抑郁的副作用。

Of course, those can be related to one another in either direction.

当然，这些可以在任一方向上相互关联。

So while I do understand that loss of one's hair or potential loss of one's hair can be particularly troubling and anxiety-provoking, even cause depression in some cases, I am sensitive to that.

因此，虽然我确实知道脱发或潜在脱发可能会特别令人不安和引起焦虑，甚至在某些情况下会导致抑郁，但我对此很敏感。

You also want to be sensitive to the fact that some of these treatments, such as finasteride, can carry very serious side effects even if you come off them, AKA post-finasteride syndrome.

您还需要注意以下事实：其中一些治疗方法（例如非那雄胺）即使您停止使用它们也可能会带来非常严重的副作用，即非那雄胺后综合症。

As long as we're talking about finasteride and this general pathway of 5-alpha reductase inhibition and thereby DHT inhibition and on and on, topics and themes and nomenclature you are now very familiar with, we have to talk about dutasteride.

只要我们谈论非那雄胺和 5-α 还原酶抑制的一般途径，从而抑制 DHT 等等，您现在非常熟悉的主题和术语，我们就必须谈论度他雄胺。

Dutasteride is yet another molecule similar to finasteride, but remember those three isoforms of the 5-alpha reductase enzyme?

度他雄胺是另一种与非那雄胺相似的分子，但还记得 5-α 还原酶的这三种异构体吗？

Well, it inhibits all three, mainly type one and type two, but also type three, and it does it very potently.

嗯，它抑制所有这三种，主要是一型和二型，但也抑制三型，而且效果非常有效。

So as a consequence, the typical dosage of oral dutasteride, get this, 0.5 milligrams to 2.5 milligrams taken orally, works two to five times faster than typical finasteride at inducing hair regrowth and reduces DHT by, get this, 95%.

因此，口服度他雄胺的典型剂量，即口服 0.5 毫克至 2.5 毫克，在诱导毛发再生方面比典型的非那雄胺快两到五倍，并将 DHT 减少，即 95%。

So it just near flatlines DHT.

所以它只是接近平线 DHT。

And that can occur at concentrations as low as 0.5 milligrams, although you will see prescriptions and people taking dutasteride anywhere from 0.5 milligrams all the way to 2.5 milligrams orally.

尽管您会看到处方和人们口服度他雄胺的剂量从 0.5 毫克一直到 2.5 毫克，但浓度低至 0.5 毫克时就会发生这种情况。

Now, not surprisingly, dutasteride is associated with a lot of side effects related to the DHT pathway, so things like reduction in sex drive, reduction in overall drive.

现在，毫不奇怪，度他雄胺与许多与 DHT 途径相关的副作用有关，例如性欲降低、整体性欲降低等。

It also tends to impact other hormone pathways, so increases in estrogen, prolactin.

它还往往会影响其他激素途径，从而增加雌激素、催乳素。

That's why gynecomastia, growth of male breast tissue sometimes occurs when people take dutasteride.

这就是为什么当人们服用度他雄胺时有时会出现男性乳房发育症（男性乳房组织生长）。

And so you're probably asking, why would anyone take dutasteride?

所以您可能会问，为什么有人会服用度他雄胺？

Why not just take finasteride and wait for that hair growth?

为什么不直接服用非那雄胺并等待头发生长呢？

Well, the answer is that people are often very impatient, and it turns out that dutasteride works about two to five times faster than finasteride.

答案是，人们往往非常不耐烦，事实证明，度他雄胺的起效速度大约是非那雄胺的两到五倍。

So some people don't want to wait a full 30 weeks or 40 weeks or 50 weeks or more in order to grow their hair back, and they're very concerned about the hair loss that's occurring.

因此，有些人不想等待整整 30 周、40 周、50 周或更长时间才能重新长出头发，他们非常担心正在发生的脱发。

So they will take what I hope would be a very low dose of dutasteride.

所以他们会服用我希望剂量非常低的度他雄胺。

I realize that there are ways to take dutasteride that can be safer, offset some of these side effects.

我意识到有一些方法可以更安全地服用度他雄胺，抵消其中一些副作用。

But by my read of the literature, if one is going to try to mildly inhibit the DHT pathway, things like saw palmetto, things like topical caffeine, which has some effect on the androgen pathway, but as we talked about earlier, tickles other pathways, things like ketoconazole, mild reduction in androgen receptor pathways in the follicle, and very direct because it's applied directly to the scalp.

但根据我阅读的文献，如果要尝试轻度抑制 DHT 通路，像锯棕榈这样的东西，像外用咖啡因这样的东西，对雄激素通路有一些影响，但正如我们之前提到的，会刺激其他通路，如酮康唑，轻微减少毛囊中的雄激素受体通路，而且非常直接，因为它直接应用于头皮。

Things like that are going to be the best route for mild reductions in DHT as an attempt to maintain hair or grow hair.

类似的事情将是轻度减少 DHT 的最佳途径，以尝试保持头发或生长头发。

Whereas if one really wants a potent stimulus for increasing hair growth, that's very likely going to be finasteride, and hopefully low enough dosages of finasteride and hopefully a patient enough patient, person, that they are willing to wait the duration of time required for that hair growth to come back because they understand that that anagen phase takes some time.

然而，如果一个人真的想要一种有效的刺激来促进头发生长，那很可能是非那雄胺，并且希望非那雄胺的剂量足够低，并且希望有足够的病人、人，他们愿意等待头发生长恢复所需的时间，因为他们知道生长期需要一些时间。

Now, the holy grail of all this hair stuff is in understanding that no one specific treatment is magic.

现在，所有这些头发材料的圣杯在于了解没有一种特定的治疗方法是神奇的。

And in fact, there are now a number of good meta-analyses comparing the various treatments we've talked about today alone or in combination.

事实上，现在有许多很好的荟萃分析来比较我们今天讨论的单独或组合的各种治疗方法。

And we can summarize that pretty easily by saying that combination treatments that involve a mechanical stimulus and a chemical stimulus are always going to be better than either one alone.

我们可以很容易地总结这一点，即涉及机械刺激和化学刺激的联合治疗总是比单独使用任何一种治疗更好。

And within the mechanical category, the stimulus that seems to work best is microneedling.

在机械类别中，最有效的刺激似乎是微针。

So the combination of microneedling and finasteride can lead to some pretty robust and impressive hair regrowth.

因此，微针和非那雄胺的结合可以使头发再生得非常健壮和令人印象深刻。

So much so that people that were, I guess we'd only describe them as pretty bald or bald, can regrow significant amounts of hair.

以至于我想我们只会将他们描述为相当秃头或秃头的人可以重新长出大量的头发。

I've never seen examples of people who were completely bald, meaning lacking all scalp hair, to grow back a full head of hair.

我从未见过完全秃顶的人，即头皮上的毛发全部脱落，却又长出一头完整的头发的例子。

But the combination of microneedling and finasteride is probably the most effective way to go.

但微针和非那雄胺的结合可能是最有效的方法。

And if you're going to do that, there's no reason why you couldn't also use ketoconazole shampoo, couldn't also use saw palmetto.

如果你要这样做，你没有理由不能使用酮康唑洗发水，也不能使用锯棕榈。

There's no reason to think that these things collide with one another.

没有理由认为这些事情会相互冲突。

Although, anytime you're inhibiting a DHT pathway or whether or not you're increasing or decreasing any hormone pathway for that matter, you want to be careful about layering in too many different treatments because you don't want your DHT level to go too low.

尽管如此，无论何时您抑制 DHT 途径，或者无论您是否增加或减少任何激素途径，您都需要小心分层进行过多不同的治疗，因为您不希望您的 DHT 水平太低。

I mean, let's keep in mind that Even if you take a very low dose of finasteride and reduce your DHT and don't have side effects, maybe just the mere addition of saw palmetto, which leads to a slight reduction in DHT, combined with some caffeine ointment, would be sufficient enough to start inducing some of the low DHT-associated side effects.

我的意思是，让我们记住，即使您服用非常低剂量的非那雄胺并减少 DHT 并且没有副作用，也许仅仅添加锯棕榈，导致 DHT 略有减少，再加上一些咖啡因软膏，就足以开始引起一些与低 DHT 相关的副作用。

So you really have to see for you.

所以你真的必须亲自看看。

And that's one of the major issues in this whole field of hair growth and regrowth, is that people are highly individual in their response and in their side effect profile to these various treatments.

这是整个头发生长和再生领域的主要问题之一，即人们对这些不同治疗方法的反应和副作用具有很大的个体差异。

But there's an enormous range there, and unfortunately, there's no way to know a priori, before doing these treatments, what your response is going to be in terms of side effects.

但其中的范围很大，不幸的是，在进行这些治疗之前，无法先验地知道您对副作用的反应是什么。

So you're simply going to have to explore, and I would hope that you would explore starting with minimal possible effective dosages, and to do that in coordination with a medical professional so you could really evaluate these things at the level of blood and cosmetic changes.

所以你只需要探索，我希望你能从尽可能小的有效剂量开始探索，并与医疗专业人员协调进行，这样你就可以在血液和美容变化的水平上真正评估这些事情。

And in fact, that's a pretty good motivator for thinking about the different treatments that we talked about today.

事实上，这是思考我们今天讨论的不同治疗方法的一个很好的动力。

Everything from mechanical treatments, as simple as massage, which we've all heard about, but for which there really aren't a lot of data for supporting hair growth.

从机械治疗到简单的按摩，我们都听说过，但实际上没有太多支持头发生长的数据。

But certainly things like microneedling, which is a mechanical stimulus for which there are pretty good data that it can improve hair growth.

但肯定是像微针这样的东西，这是一种机械刺激，有相当好的数据表明它可以改善头发生长。

Also things like saw palmetto, a weak DHT antagonist.

还有像锯棕榈这样的东西，一种弱的 DHT 拮抗剂。

Also things like ketoconazole shampoo, which again, is a weak DHT antagonist and operates through some other pathways as well to stimulate hair growth.

还有像酮康唑洗发水这样的东西，它也是一种弱的 DHT 拮抗剂，并通过其他一些途径来刺激头发生长。

My suggestion is that anyone, young, old, male, female, who's thinking about embarking on various treatments for offsetting hair loss and stimulating hair growth, consider both mechanical approaches and the approaches that attack the chemical pathways that can stimulate hair growth and can inhibit the inhibitors of hair growth.

我的建议是，任何正在考虑采取各种治疗方法来抵消脱发和刺激头发生长的人，无论年轻、年长、男性还是女性，都应考虑机械方法和攻击化学途径的方法，这些化学途径可以刺激头发生长并抑制头发生长的抑制剂。

In fact, that's the reason why we spent so much time on the biology of hair growth and what shuts down hair growth early on in today's episode, and then systematically went through each of the various treatments that relies on, and in some cases hinges entirely on, either a mechanical stimulus or a chemical stimulus in order to exert its effects.

事实上，这就是为什么我们在今天的节目中花了这么多时间来研究头发生长的生物学以及停止头发生长的原因，然后系统地介绍了每种依赖于（在某些情况下完全取决于）机械刺激或化学刺激以发挥其效果的治疗方法。

My goal today was not to overwhelm you with a ton of biology about hair, although we did cover a lot of biology of hair and stem cells and hair growth.

我今天的目标不是用大量有关头发的生物学知识让您不知所措，尽管我们确实介绍了很多头发和干细胞以及头发生长的生物学知识。

My goal in describing all that was really for you to be able to hear about various treatments, whether or not it's lasers or PRP or finasteride, dutasteride, or whatever is coming next that we're sure to hear about soon online and from the medical community, and to be able to place those into bins related to their known or potential mechanisms.

我描述这一切的目的实际上是让您能够听到各种治疗方法，无论是激光、PRP、非那雄胺、度他雄胺，还是接下来我们肯定很快会在网上和医学界听到的任何治疗方法，并能够将它们放入与其已知或潜在机制相关的垃圾箱中。

And then to be able to step back and evaluate which, if any, of those treatments might be right for you.

然后能够退后一步，评估哪些治疗方法（如果有的话）可能适合您。

If you're learning from and/or enjoying this podcast, please subscribe to our YouTube channel.

如果您正在学习和/或喜欢此播客，请订阅我们的 YouTube 频道。

That's a terrific zero-cost way to support us.

这是支持我们的绝佳零成本方式。

In addition, please subscribe to the podcast on Spotify and Apple.

此外，请订阅 Spotify 和 Apple 上的播客。

And on both Spotify and Apple, you can leave us up to a five-star review.

在 Spotify 和 Apple 上，您都可以给我们五星级的评价。

If you have questions for me or comments about the podcast or guests you'd like me to include on the Huberman Lab podcast, please put those in the comments section on YouTube.

如果您对我有疑问或对您希望我在 Huberman Lab 播客中加入的播客或嘉宾有意见，请将这些意见放在 YouTube 的评论部分。

I do read all the comments.

我确实阅读了所有评论。

Please also check out the sponsors mentioned at the beginning and throughout today's episode.

另请查看今天节目开头和整个节目中提到的赞助商。

That's the best way to support this podcast.

这是支持这个播客的最佳方式。

During today's podcast and on many previous episodes of the Huberman Lab podcast, we discuss supplements.

在今天的播客和休伯曼实验室播客的许多以前的剧集中，我们讨论了补充剂。

While supplements aren't necessary for everybody, many people derive tremendous benefit from them for things like enhancing sleep, hormone support, focus, and more.

虽然补充剂并不是每个人都需要的，但许多人从它们中获得了巨大的益处，例如增强睡眠、激素支持、注意力等等。

If you'd like to see the supplements discussed on the Huberman Lab podcast, you can go to Live Momentous, spelled O-U-S, livemomentous.com/huberman.

如果您想查看 Huberman Lab 播客上讨论的补充内容，可以访问 Live Momentous，拼写为 O-U-S，livemomentous.com/huberman。

If you're not already following me on social media, I am hubermanlab on Instagram, Twitter, Facebook, and LinkedIn.

如果您还没有在社交媒体上关注我，我是 Instagram、Twitter、Facebook 和 LinkedIn 上的 hubermanlab。

And especially on Instagram, I cover science and science-related tools, some of which overlaps with the content of the Huberman Lab podcast, but much of which is distinct from the content of the Huberman Lab podcast.

特别是在 Instagram 上，我介绍了科学和科学相关的工具，其中一些与 Huberman Lab 播客的内容重叠，但其中大部分与 Huberman Lab 播客的内容不同。

Again, it's hubermanlab on Instagram, Twitter, Facebook, and LinkedIn.

同样，它是 Instagram、Twitter、Facebook 和 LinkedIn 上的 hubermanlab。

And if you haven't already subscribed to our Huberman Lab podcast Neural Network Newsletter, this is a zero-cost newsletter that we send out each month.

如果您还没有订阅我们的 Huberman 实验室播客《神经网络通讯》，这是我们每月发送的零成本通讯。

It includes summaries of podcast episodes, and we have what are called toolkits.

它包括播客剧集的摘要，我们有所谓的工具包。

Those toolkits range from how to optimize your sleep to how to optimize neuroplasticity.

这些工具包的范围从如何优化睡眠到如何优化神经可塑性。

We have toolkits for dopamine, we have toolkits for deliberate cold exposure, heat exposure, exercise, and much more.

我们有多巴胺的工具包，我们有用于故意冷暴露、热暴露、锻炼等等的工具包。

Again, it's totally zero cost to sign up.

再次强调，注册成本完全为零。

You simply go to hubermanlab.com, go to the Menu tab, scroll down to Newsletter, and supply us your email.

您只需访问 hubermanlab.com，转到“菜单”选项卡，向下滚动到“时事通讯”，然后向我们提供您的电子邮件。

We do not share your email with anybody.

我们不会与任何人分享您的电子邮件。

Thank you for joining me for today's discussion, all about the biology of hair and hair growth, how to hold on to the hair you have, and to stimulate new hair growth.

感谢您参加今天的讨论，讨论的主题是头发和头发生长的生物学、如何保留现有的头发以及刺激新头发的生长。

And last but certainly not least, thank you for your interest in science.

最后但并非最不重要的一点是，感谢您对科学的兴趣。