Trans Summer School: Estrogen


If you’re a little older, or you feel confident and ready to transition after being on blockers and your doctor thinks it's reasonable to do so, you may start taking estrogen and an androgen blocker if your body would otherwise naturally produce testosterone. You may hear estrogen referred to as a “feminizing hormone” or “female hormone,” which is a term I dislike because you may not necessarily be taking it to achieve a “feminine” body if you’re nonbinary or otherwise gender nonconforming, and lots of people who aren't women produce estrogen naturally. You can just call it estrogen!

Before starting HRT, your doctor will order some blood work (or a “blood panel”) to check out your current hormone levels, liver and kidney health, cholesterol levels, and other major health indicators. They may want to conduct a physical, and they will also review the effects, risks, and benefits of hormones. Requesting information about hormones doesn’t mean you need to start right away: you (and possibly your parents) may sign an informed consent form indicating that you understand the details of the treatment, and you may be able to get a prescription that day, but you can also wait! Hormones are a big decision, and no one wants to push you into it.

Estrogen has a number of effects on the body. It will cause breast development (we can’t guarantee your cup size, though!), will force fat to redistribute (giving you fuller hips, among other things), and tends to soften skin. A number of chemical formulations are available and the one your doctor recommends will depend on where you are and the specifics of your case. 17-beta-estradiol tends to be quite popular at the moment.

Androgen blockers (anti-androgens) are usually prescribed alongside estrogen. They offer benefits that estrogen can’t, like stopping or preventing baldness, limiting facial hair growth, and reducing spontaneous erections. They offer another benefit, too: when you take anti-androgens, you can reduce your dose of estrogen, thereby avoiding some potential side effects. You can also take an anti-androgen alone, without estrogen, if you want to block testosterone in your body but not develop the physical traits associated with estrogen therapy.

Progestagens may come up as well in discussions about your HRT, though they aren’t in widespread use. Some physicians may use them to supplement estrogen, or as an estrogen alternative if they’re concerned about side effects.

How is it administered?

Estrogen is available in a number of formats, including pills, gels, patches, and injections. Researchers have found that when estrogen is delivered transdermally (gel or patch), the risk of blood clots and elevated triglycerides (bad fats) tends to be lower. For this reason, trans people over 40 who use estrogen often take it transdermally, and your doctor may recommend this method for you if you have a family history of these problems.

Anti-androgens are delivered in pill format, and progestagens come in both pill and cream form.

What are the risks?

HRT can be risky, and the best way to reduce that risk is to work closely with your doctor. You may need to try several drugs and a variety of dosages to find the ones that work for you, and you will need regular blood work to monitor your hormone levels. Never take more than prescribed, even if you’re impatient for some changes, because you can experience serious side effects. Among other things, if you have too much estrogen in your body, an enzyme called aromatase can actually convert it into testosterone, which is the last thing you want! If you choose to have an orchidectomy (removal of the testicles), you will be able to reduce your hormone dosage since your body won’t be producing testosterone anymore.

One significant risk of estrogen therapy is blood clots, a known issue in people who produce estrogen on their own as well. If you smoke, that risk is greatly elevated, which is another excellent reason not to start smoking. People on estrogen therapy can also experience a loss of bone density, and your doctor may recommend supplements to address this problem. That fat migration that many people are excited about, because it changes their shape, can cause abdominal fat deposits, which are potentially dangerous. Estrogen can also contribute to the development of gallstones and high blood pressure. Some patients develop nausea, vomiting, or headaches — if these are severe, or they don’t stop as you get used to the medication, you should talk to your doctor.

Liver stress is another issue, because your liver is responsible for processing these drugs, so your doctor may recommend periodic liver enzyme level testing to keep an eye on things. You may also want to discuss whether you should make some lifestyle or health care changes, like drinking less or avoiding certain medications, to protect your liver. This can be especially important with psychiatric medication, as many psychiatric drugs, like depakote, interact with your liver. Make sure all members of your health care team know you are on HRT so they can work around potential drug interactions.

Anti-androgens, which are processed by your kidneys, can carry a separate risk of kidney problems. It’s important to stay hydrated, discuss potential drug interactions with your doctor, and get regular bloodwork to check your levels. While estrogen can cause high blood pressure, anti-androgens can potentially cause low blood pressure and cardiac arrythmias. Some people develop skin rashes, which should always be reported to your doctor.

Fertility is also a concern. Though changes from hormones are theoretically reversible, we don’t know enough about fertility after cessation of HRT, because it’s not an issue that comes up very frequently. We do know that estrogen and anti-androgens make it harder to produce sperm. If you are worried about contributing your genetic material to a child in the future, you should talk about sperm banking before you start HRT. If thinking about that seems a little intense right now, you might want to take some more time to think!

What are the side effects?

I’m separating these out from “risks” because they involve the effects of estrogen and anti-androgens on your body. Some side effects, like breast growth, softer and more sensitive skin, and fat migration, are desirable. You will also notice a decreased sex drive, fewer erections, a reduction in ejaculate volume, slower facial and body hair growth, and a reduction or complete stop in balding — something you probably aren’t experiencing yet, we hope. These changes (with the exception of breast growth) are reversible: if you stop taking estrogen, your body will reorient itself, and you need to stay on HRT for life.

Many people experience emotional changes on HRT, and no, not for the stereotypical reasons. With the right hormones in your body, you may feel calmer, more relaxed, and better able to handle the problems of the world. The physical changes may also be very affirming, and while HRT can’t magically fix body image issues, it can definitely be a step in the right direction: being more comfortable with who you see in the mirror can make you feel a whole lot more confident. Simply progressing on the pathway to transition also makes a difference for some people, who may find that HRT helps with depression and anxiety by giving them something positive to focus on.

It usually takes about two years for your body to “settle” on HRT, which is good to keep in mind if you are considering breast augmentation. It’s a good idea to let your breasts fully develop so you know what you have to work with before you meet with a reconstructive surgeon.

One “benefit” of growing breasts is that you may be at risk for breast cancer, although the jury is still out. We do know that people with a family history of breast cancer are at higher risk, and adding estrogen to your body could elevate that risk. Talk to your doctor about your family history to determine if you need to take special care with screening or preventative care. You just grew those babies, you don’t want to have to send them back to the factory!

This page is a section of the article Trans Summer School: The Magic of Hormones. To read the full article, or to navigate to another section, click here