Feminizing hormone therapy: A guide to the medications, body effects, and health risks you should know about

• Feminizing hormone therapy often involves taking estrogen and anti-androgen hormones, such as estradiol or spironolactone. 
• By taking these hormones, you may be able to achieve more traditionally feminine characteristics, including breast growth, body fat redistribution, and less facial hair. 
• To determine if feminizing hormone therapy is right for you, it’s important to visit a qualified medical professional who can help you with the dosage necessary to achieve your desired effects. 
• This article was medically reviewed by Zil Goldstein, the associate medical director of Transgender and Gender Non-Binary Health at Callen-Lorde Community Health Center in New York.
• Visit Insider’s Health Reference library for more advice.

Feminizing hormone therapy is a common way for transfeminine or gender non-binary individuals to achieve traditionally female characteristics and feel more comfortable in their own bodies. Here’s how it works, what you can expect from the procedure, and important health risks to know. 

What is feminizing hormone therapy?

Feminizing hormone therapy can involve taking estrogen and anti-androgen hormones. An anti-androgen is any drug that blocks the production of male sex hormones, mainly testosterone. 

“We’re increasing estrogen levels while also decreasing testosterone levels,” says Ravi Iyengar, MD, an endocrinologist at Rush University Medical Center with a clinical expertise in transgender medicine. 

Ultimately, the target is to lower the patient’s testosterone levels to that of the typical cis female range, which is around 30 to 100 ng/dl. The following medications are usually used: 

• Estradiol. This estrogen hormone is taken in a pill, gel, patch, or injectable form. Daily oral doses of estradiol fall around 2 to 4 mg daily, according to a 2019 study, though the dose can increase up to 8 mg. Users take the dose for as long as they want to see feminizing effects in their bodies. 
• Spironolactone. Though this medication was originally used to lower blood pressure, it has been found to lower androgen hormone levels in users. It is now the most commonly used androgen blocker for feminizing hormone therapy. Spironolactone is taken orally once or twice a day, at doses of 100 to 200 mg. 

How might your body change? What to expect 

“I usually talk to most of my patients that, in general, hormone therapy is not quick to act. It’s a process and it does take a couple of years,” Iyengar says.

Here is a general timeline and description of the changes you might expect from feminizing hormone therapy: 

• Body fat redistribution. Body fat moves toward the hips, legs, cheeks, and face to create a more feminine fullness. Muscles in the arms and legs will appear less defined, and more fat forms under the skin. 
• Breast growth. Fat will also appear on the breasts, and you may be able to form an "A" cup or a small "B" cup, though results are highly variable, and can differ for everyone. You will also develop mammary and ductal tissue, which is important to note because you will require breast cancer screenings in the future. 
• Hair and skin differences. Your facial or body hair will become finer. Any receding hairlines or balding on top of the head will stop. Your skin will also become softer and less oily. 
• Decreased sperm count. Estrogen drugs and spironolactone can lower sperm count, making it potentially more difficult to produce biological children, according to the University of Utah Health's transgender health program. 

To develop the right individualized treatment plan, you should talk with your doctor about what you'd like to gain from feminizing hormone therapy and your preferred timetable, as you can adjust your dosage accordingly. 

How should you prepare? Health risks to know 

The lower your dose of feminizing hormones, the slower the changes you'll see in your body. However, this doesn't necessarily mean that higher doses cause faster changes, and they may even endanger your health. 

In fact, high doses of estrogen can increase the risk of blood clots, stroke, and estrogen-related tumors, according to a 2018 study. That's why preliminary blood tests are important for those seeking to go on feminizing hormone therapy.

"Every person is unique based on their own health factors and their family history," says Amy Weimer, MD, a primary care physician with a clinical interest in transgender care at UCLA Health. "But at the very baseline, we typically check blood count and a liver and kidney panel, then may check tests for cholesterol or diabetes or occasionally hormone levels as well."

Blood clots are the best characterized risks for estrogen therapies, says Joshua Safer, MD, an endocrinologist at the Center for Transgender Medicine and Surgery at Mount Sinai Hospital. However, they're not common. A 2017 study found that blood clots form within roughly two of 1,000 people on feminizing hormone therapy. 

Those taking spironolactone must also know their baseline potassium levels. Spironolactone is known as a potassium-sparing diuretic, meaning it prevents the body from having low potassium levels. The drug blocks the hormone aldosterone, which causes the kidneys to pass fluid while keeping potassium. 

In some cases, potassium could build up to higher than normal levels in a condition called hyperkalemia, though it is also rare.  You should check in with your doctor if you experience the following symptoms of hyperkalemia: 

• Muscle weakness, numbness, or tingling
• Nausea or vomiting 
• Heart palpitations
• Shortness of breath
• Chest or muscle pain 

Weimer also says there are a few medical cases where feminizing hormone therapy may be more harmful to your health, such as having signs of breast cancer, colorectal cancer, or any cancer sensitive to estrogen. 

Takeaways

While feminizing hormone therapy comes with some health risks, for some people, not receiving this treatment can be even more harmful. "It is, for many people, a life-threatening condition to continue without access to hormone therapy," Weimer says. "It carries its own very high health risk."

To find an expert well-versed in transgender care, try to find a WPATH provider near you. WPATH stands for World Professional Association for Transgender Health and aims to promote evidence-based care, education, research, public policy, and respect in transgender health. Other good places to look for a provider include LGBT centers, community health centers, or community clinics, says Weimer. 

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