Transgender and nonbinary  people might make up somewhere around three percent of the world’s population, though it’s hard to come up  with an accurate estimate.

Many such people seek medical interventions to help their bodies reflect their identities. And the more we learn, the more we understand that trans healthcare saves lives.

Trans populations are vulnerable  to violence and self-harm, and acceptance and affirmation  are ways to reverse that. One of the most accessible interventions is the use of hormone replacement therapy, or HRT, to create masculinizing or  feminizing changes in the body. Today, we’re going to pull back  the veil and take a look at exactly how these kinds of treatments work.

If you’re considering it for yourself, you can get a sense of what to expect. For everybody else, we hope  to eliminate the stigma and show that this is safe and  effective means of healthcare. So now for a video that will  stir up no controversy whatsoever and generate nothing but friendly comments: Actually understand HRT. [♪ INTRO] First up, just so ya know, we  here at SciShow think trans and nonbinary people should have  a voice in their own healthcare.

That’s why this video was pitched,  written, and hosted – hi – by trans and nonbinary members of our team. If you don’t like cis people telling  you how to live your lives, great! Neither do we.

That said, we also want this video to be helpful to anyone curious about  HRT, whether you’re a parent to a trans youth or maybe wondering about the changes a friend is going through. Or you just wanna know how the stuff works. Ok, let’s talk sources.

Navigating trans healthcare  can be incredibly difficult, but there are some rock solid resources  out there to take advantage of, and we’ll be using them a lot today. One is the World Professional  Association for Transgender Health, or WPATH, which published the eighth edition of their Standards of Care in 2022. This is intended to provide  guidance to healthcare professionals around the world for how to deal  with trans patients respectfully and with their health and safety at the forefront.

Another source we’ll be using a lot is the UCSF Transgender Care guidelines. Some of this information is slightly  out of date, going back to 2016, and they have a big revision pending in 2024. However, they have the advantage  of rating the quality of clinical evidence for or  against certain practices, like which formulation of hormones to use or whether your doctor should  monitor for certain side effects.

Next, let’s establish some terms. You may be familiar with the  phrase hormone replacement therapy, which refers to using hormones to accomplish a masculinizing  or feminizing effect. However, there’s increasing  support for a different term: gender-affirming hormone therapy.

That’s because HRT was first used to describe adjusting hormone levels in cisgender people. The phrase “gender-affirming”  instead centers us and our choices. I’m going to mostly say HRT  because if I am brutally honest, it is easier to read off a teleprompter.

There’s another term I just used: cisgender, which refers to anyone whose  gender identity generally matches the sex they were assigned at birth and who doesn’t experience  genderweirdness day to day. Couldn’t be me. For the rest of us, the  experience of gender is so diverse that it’s hard to capture in just a few words.

WPATH uses the catch-all term  transgender and gender diverse, or TGD for short, while acknowledging that no catch-all really catches us all. Now that all that housekeeping’s out of the way, let’s start out by talking about  how you can get access to care. After that, we’ll start going  into some details of how hormone therapy works in adults and adolescents.

The medical community as a whole is moving away from pathologizing TGD folks  – that is, from viewing us as having some kind of mental disorder. The DSM-5 – basically the Bible of  all things psychology diagnoses – does still categorize gender  dysphoria as a mental disorder. Meanwhile, the ICD-11, a handbook of diseases, lists gender incongruence instead.

See, WPATH recommends treating TGD folks based on informed consent. That’s where you give patients  enough information for them to clearly understand the risks  and benefits of treatment, and let them make their own decisions. And while it’s good that the  medical community is moving away from treating us like some kind of problem, there are still reasons you might need to have one of these diagnoses in your hot little hands.

But you may not have access to a provider who operates under this framework, and your doctor may instead require a diagnosis and monitoring over a period of  time before they agree to treatment. If you live in the UK and are trying  to access care through the NHS, for example, you’ll need a referral  to a specialist gender clinic to even obtain a diagnosis  before beginning treatment. Which, again, is contrary to what  WPATH recommends, but I digress.

Even if your doctor is the most  enlightened person in the world and operates under informed  consent, your insurance company might look for excuses to  not pay for your healthcare, so to get them to cough up enough, you might need a diagnosis and monitoring anyway. Which might not be transphobia so much as an equal-opportunity failure of the system… In other words, think of getting  a diagnosis of gender dysphoria or gender incongruence not as  showing something’s “wrong” with you, but as ammo for navigating a challenging system. Now, let’s get into some specifics of how hormone treatment actually works.

My momma raised me to be polite,  so let’s start with ladies first. Feminizing hormone therapy is going  to involve taking both estrogen, the hormone that influences the development of feminine secondary sex characteristics, and a medication to block the  testosterone your body makes. Some people may add progesterone on top of that, but WPATH doesn’t recommend doing so, and I’ll get into why in a second.

Estrogen comes in a few forms, but  doctors favor 17-beta estradiol because it’s identical to the  form produced in the human body. Equine-derived estrogens are also out there, but not necessarily recommended because they come with some risk of blood clots. Estradiol is available as a  pill, patch, or injection.

Most doctors will aim to achieve levels comparable to what’s in a cisgender woman’s body, though it’s probably worth noting that we’re still figuring out exactly what to shoot for. It’s not really settled science. Depending on how much a patient  needs to achieve that level, they might take anywhere from one  to eight milligrams a day via pill, 50 to 400 micrograms at a time via patch, or one to 20 milligrams a week via injection, depending on which of two  formulations they’re using.

In addition to this, providers will  usually add an androgen blocker to suppress the amount of testosterone  being made naturally by the body. That’s because while estrogen will knock levels of testosterone down  some, it won’t take them all the way down to where a cis woman would be. The most commonly used option is spironolactone, though providers may also recommend  finasteride or dutasteride, medications also approved for things  like hair loss in cisgender men.

Now, about progesterone. There are widely circulated  anecdotal claims that adding progesterone will enhance breast development, something a lot of trans women  will probably find appealing. However, the clinical evidence  for this actually isn’t great.

What’s more, some studies  have found that progesterone can increase the risk of blood clots. It’s important to talk to your  doctor about your goals, of course, but they may advise that the potential  benefits don’t outweigh the risk. Instead, UCSF suggests that it  may be possible to enhance breast development by starting with a low  and escalating dose of estrogen, then adding in spironolactone later, though unfortunately the evidence  for this is also not great.

So what can you actually  expect from estrogen therapy? Breast tissue growth is all but certain, though it might take two or three  years to reach the full effect. And you most likely won’t reach the full development a cisgender woman would.

The body will also redistribute some fat, including to the hips and thighs. It’s a myth that hormone therapy  will affect your bone structure, unless you start very young. But fat shifting in your face might result in a more feminine appearance.

You might also see softer skin,  fuller hair on your scalp, lower muscle mass, and changes to your sex drive. Unfortunately, one thing estrogen  won’t do is change your voice. There are other ways to accomplish  that, just not this one.

Some folks might also experience  a decrease in sexual function, but apparently – and I am  reading this right off of UCSF – you can ask for the ol’ blue pill. Hormones can also affect your mood, but we should be careful not  to let our interpretation of those effects come out as plain old sexism. Some people might experience  a broader emotional range, but let’s not call them “mood swings.” Because a lot of people will  feel just plain better on HRT – their brains are finally  running on the right juice.

Nearly all of these changes are  reversible if HRT is discontinued – other than breast growth. Of course, the changes that  come with hormone therapy are pretty unique to the individual. It’s impossible to know  exactly what changes you’re going to get ahead of time, so  discuss it with your doctor.

Speaking of your doctor, they’ll  probably want blood tests every 3 months in the first year  to check your hormone levels and adjust your dosage if necessary. They might also want to monitor  for certain side effects, though there’s a lack of  consensus on which side effects you should really worry about. For example, estrogen can affect the composition of your blood  lipids, like cholesterol.

Back in 2016, UCSF found no evidence  to support routine monitoring. The literature since then seems pretty mixed, but it seems some of those  changes can actually be positive! Another thing to keep an eye on  if you’re using spironolactone is kidney function, since it can  lead to high potassium levels, but this is unlikely to be a huge  risk as long as you monitor it.

And as I’ve already hinted more than  once, another risk is blood clots. It doesn’t seem to be a big risk,  just one that’s difficult to rule out, so your doctor may want to  add some extra monitoring if you have other risk factors,  like a history of smoking. And if you do smoke, your doctor  will likely advise you to quit.

Finally, the decision to have  children is a personal one. But if that matters to you,  it’s important to know how estrogen therapy can affect your fertility. Which is why it’s also important  to know that while estrogen may decrease sperm count and affect semen quality, WPATH identifies this as a gap in our knowledge.

It’s really important that we  study this more so that people can make the best decisions for their own futures. Ok, here comes the part where our writer Alex actually has personal experience with! In other words, we’re moving on to testosterone.

Where the medications are concerned, this is much simpler compared to estrogen therapy, because you need to take one  thing and one thing only. Testosterone is usually administered by injection or as a gel applied to the skin. Other formulations exist, but aren’t used as often to treat trans men specifically.

Injections can be intramuscular, meaning injected into the muscle like a flu shot. Or they can be subcutaneous  – injected into the body fat. Either way the dosage can be anywhere from 20 to 100 milligrams a week.

Alex would like to submit that  the subQ route is very easy if you are not afraid of needles,  but please make sure your doctor gives you some basic needle safety knowledge and a way to dispose of them correctly. For the love of everything holy,  do not share or reuse needles. Don’t do it.

If you need an incentive,  using needles dulls the point, making subsequent injections more painful. The gel is a great alternative if you are still intimidated by the shots thing, but you do need to make sure it dries all the way so it doesn’t spread to other  members of your household who didn’t consent to treatment. Now, as far as what you can actually expect.

Testosterone will cause  redistribution of body fat, similar and opposite to estrogen, which may send more fat towards your belly and give you a more masculine facial profile. You may see oilier and rougher  skin, increased muscle mass, and changes to your sex drive, and  your periods will probably stop. That stuff is generally considered  reversible if you stop treatment.

However, some changes are permanent and won’t go away if you discontinue testosterone. Fortunately, the irreversible  changes are also the ones a lot of trans dudes are specifically after: a deeper voice and facial hair growth. There’s also what’s euphemistically  called “bottom growth,” that is, permanent enlargement of  the clitoris by a couple centimeters.

Vaginal atrophy can also happen, which can be treated with topical estrogen. You may experience quote-unquote  “male” pattern baldness, and your doctor can prescribe hair  loss medication if that’s the case. Also, butt hair.

So much butt  hair. You will grow butt hair. Emotional changes can happen  too, but I’d like to repeat what I said before about  being careful not to interpret those changes in the context of our  traditional perceptions of gender.

Testosterone won’t necessarily make  you prone to anger or “roid rage.” Some people report finding  it more difficult to cry. But a lot of people seem to feel  more centered and calm – not angrier! Just like with estrogen, your doctor will probably want a checkup every three  months in the first year of treatment to check the levels  of testosterone in the blood.

Also just like with estrogen,  the quality of evidence for what side effects to  look out for is kinda mixed. The big thing is that testosterone  can increase your blood count, so your doctor will probably want to do a blood panel every once in a while. Like estrogen, testosterone can  affect your blood lipid levels, but the evidence for routine  monitoring is lacking.

Finally, let’s return to fertility. Your menses will most likely stop on testosterone, especially higher doses, but that  doesn’t necessarily make you infertile. A 2024 study found that a third  of transmasculine individuals on testosterone therapy who aren’t  having periods are still ovulating.

So if you have a sexual  partner who produces sperm, birth control is your safest  bet to prevent pregnancy. Conversely, it is possible for  some trans men who discontinue testosterone to get pregnant  and have healthy kids. As always, it’s about talking to your  doctor about your goals and needs.

Now, a quick message for  my fellow nonbinary folks. How you doin’? Is that a new shirt?

That’s not the message, I just wanted to say hi. The message is this: The great  thing about being nonbinary is that we get to decide what that means, but the flip side of that is that it’s pretty hard to provide any one-size-fits-all advice. So while there aren’t a lot of  specific resources out there targeted at nonbinary people, there are some.

And a lot of what I’ve already said about estrogen and testosterone applies here as well. Lower doses of hormones can result  in a more gender-neutral effect compared to the doses prescribed  to trans men and women. And there are a few additional  ways to customize treatment for whatever you personally want to accomplish.

According to UCSF, people  whose bodies produce mainly testosterone can use an androgen  blocker without additional estrogen. As another example, if you have  periods and don’t want to, but don’t want to go on a high dose of  testosterone, a contraceptive that stops your periods might  be what you’re looking for. The most important thing to  keep in mind is that you can’t really use hormones to pick out  masc or femme traits a la carte.

Hormones are gonna do what they’re gonna do. In particular, WPATH notes that estrogen treatment pretty much inevitably comes  with some breast growth. Likewise, testosterone will likely come with a change in voice pitch and some genital growth.

The important thing is to make  your goals clear to your provider, so you can decide together what’s  the best way to get you there. All of this so far has focused on TGD adults. What I’m going to do now, given  the current state of politics, is kick a hornet’s nest.

But it’s an important thing  to say, because care for TGD minors is medically  necessary and can be life-saving. In the United States alone, the  American Academy of Pediatrics, the American Medical Association, and the American Academy of  Child and Adolescent Psychiatry all back gender-affirming care for kids and teens. The main treatment for TGD kids  comes in the form of gonadotropin releasing hormone agonists, often  referred to as puberty blockers.

These molecules kick off a chain reaction of hormonal signaling in the  body that eventually causes it to stop making estrogen and testosterone. Without those hormones, the body  simply can’t go through puberty. Indeed, we know this treatment  is safe and effective because it’s been used to treat early puberty  in cis children for a long time.

The effects are completely reversible, and it’s considered a useful tool  to give the individual more time to understand their identity and  their needs before undergoing either HRT or their own endogenous puberty. One thing worth noting is  that WPATH doesn’t recommend starting puberty blockers until the  individual has started puberty – what’s referred to medically as Tanner stage 2. This might seem a little scary,  as the irreversible changes caused by puberty are something that those  patients likely want to avoid.

However, treatment with puberty  blockers at that time will put you back to Tanner stage  1, which is prepubescent. So all this really does is make sure a child isn’t taking medication they don’t  need, until they need it. Puberty blockers can also  be started at a later time, though they won’t turn back the clock all the way if a child has begun endogenous puberty.

It’s also possible to stop someone’s periods without puberty blockers and  without starting testosterone. And no points for guessing  this one, because it can be extremely similar, in some cases  identical, to hormonal birth control. Doctors can also initiate  hormone therapy after evaluating the patient and obtaining informed consent.

Rather than giving an adult dose,  they’ll probably try to mimic the course of puberty by  ramping up levels over time. There you have it: all the  questions we could think of to answer regarding  gender-affirming hormone therapy. There’s one final option I’d  like to discuss, and that’s: not going on HRT at all.

Because our bodies don’t have to be medicalized. Your transition should be  whatever you want it to be, and if that’s never touching hormones or surgery, you’re perfect and I love you. There’s also the fact that  cultures all over the world have had all different kinds  of ways to understand gender long before we invented this  modern medical technology.

They were, and are, totally valid without it! Still, we hope that this has  been helpful for everyone who does want to learn more about  gender-affirming hormone treatments. If you have more questions, feel free to throw them in the comments, and we’ll see you next time. [♪ OUTRO]