Feminizing hormone therapy includes medications that will reduce the level of testosterone while providing enough estrogen (or estradiol) to allow feminizing changes to occur. It is important to let your provider know if you take any other prescribed medications or over-the-counter supplements as these may interfere with feminizing medications.
Estradiol serves two roles in feminizing treatment:
Estradiol can be given in many ways, most commonly, oral, transdermal or injectable. Your provider should review the pros and cons of each of these. It is important to review your medical history with your provider particularly if you have a history of cancer (including breast or prostate), heart disease, stroke, blood clots, liver disease or smoking, because your risks associated with hormone therapy may be increased if you have any of these. Risks related to estradiol therapy may include increased risk of blood clots, change in cholesterol profile, high blood pressure and possibly heart disease/stroke, particularly if you are older than age 50 years.
Because the risk of blood clots with estrogens seems related to total dose, most feminizing treatment includes other testosterone lowering or blocking medicines in addition to estradiol. In the United States, the most common medication against testosterone is spironolactone. Spironolactone pills may block the effects of testosterone and also reduce the levels in the blood. With the fall in testosterone level, you may notice breast tenderness. The most other common side effects include increased urination, risk of high potassium and possibly lower blood pressure. Your provider will monitor your potassium levels. If these side effects are too significant, speak to your health care provider about alternatives.
Physical changes may take some time to occur. Below we have provided a general expected timeline. It is important to know that everyone is different. Your height, voice and Adams apple will not change with hormone therapy.
Feminizing hormones will decrease sperm production; however it is still possible to get your partner pregnant if you engage in vaginal sex. You may need to use additional birth control measures. If you wish to have children in the future, consider banking sperm before starting hormone therapy.
Your provider will recommend that you regularly come for follow up care after these hormones have started. Follow up visits may include physical examinations, measurement of hormone levels and sometime other testing depending on your age and medical problems. Other tests may include a bone density, mammogram, prostate assessment, sexually transmitted infection (STI) screen and follow up of blood sugar and cholesterol. If you are older than 50 years of age, your doctor may want to evaluate your risk of heart disease a little more carefully.