Risks of Estrogen Hormone Therapy

This article is part of a series on the impacts of hormone replacement therapy (HRT), designed to help our clients (and others!) prepare for possible changes they may experience as they begin their hormone journeys.

It wouldn’t be responsible to talk about hormone replacement therapy (HRT) without discussing the risks and benefits of treatment. All medications come with risks, but there are many myths about the health risks of estrogen hormone treatment. Therefore, we have also included some reassuring facts that may help alleviate those concerns.

Click here to read the full article by Dr. Maddie Deutsch, Associate Professor of Clinical Family & Community Medicine at the University of California – San Francisco (UCSF), and Medical Director for UCSF Transgender Care.

Risks

• The biggest increase in risk when taking estrogen occurs when it is combined with cigarette smoking. In this case, there is a notable increased risk of blood clots and a likely increase in strokes and heart attacks. These risks can be mitigated by changing the mode of estrogen delivery from injection to patch or other topical form.

• In those who don’t smoke, hormone therapy may still correlate with a slight increase in the risk of blood clots, heart attacks, strokes, diabetes, and cancer. The risks are higher for those with co-existing health conditions and those who start hormone therapy after age 50. The increase in risk may be offset by quality-of-life improvements and reductions in stress levels.

• Since there is not a lot of research on the use of estrogen for feminizing treatment, there may be other unknown risks, especially for those who have used estrogen for many years.

Rare Risks

• While gender-affirming hormone therapy usually results in an improvement in mood, some people may experience mood swings or a worsening of anxiety, depression, or other mental health conditions as a result of second puberty. If you have any mental health conditions, you may choose to remain in discussion with a mental health provider as you begin hormone therapy.

• Some medical conditions, such as autoimmune disorders and migraines, have a hormonal component and thus may be impacted by gender-affirming hormone therapy, though research is lacking. Ask your medical provider if you have further questions about the risks, health monitoring needs, and other long-term considerations when taking hormone therapy.

• Modern, healthy approaches to estrogen therapy have no risk of causing liver injury. However, in rare cases, the flow of bile from the liver through the gallbladder may be slowed as a result of hormone therapy, which can lead to an increased risk of gallstones.

Reassurances

• It is possible that the risk of prostate cancer decreases with hormone therapy, but there is not enough research to know for sure.

• The risk of breast cancer may increase slightly with hormone use, but will still be much lower than the risk in a non-transgender female.

• For those over 50, it might be appropriate to use testosterone blockers only, reducing or even eliminating the dose of estrogen (thus removing the health risks that accompany estrogen use for individuals of this age). Since most non-transgender women go through menopause with declining estrogen levels at age 50, this approach is similar to the natural female life course and may be of particular value in those with other health risks.

• For those who have had an orchiectomy or vaginoplasty, you will be able to stop taking testosterone blockers and may be able to take a lower dose of hormones, but should remain on at least a minimal dose of hormones until age 50. This will help prevent a potentially severe weakening of the bones, otherwise known as osteoporosis, which can result in serious and disabling bone fractures.

• Many of the effects of hormone therapy are reversible if you stop taking hormones. The degree to which they can be reversed depends on how long you have taken them. Breast growth and infertility may not be reversible.

Risks of Testosterone Hormone Therapy

It wouldn’t be responsible to talk about hormone replacement therapy (HRT) without discussing the risks and benefits of treatment. All medications come with risks, but there are many myths about the health risks that come with testosterone treatment. Therefore, we have also included some reassuring facts that may help alleviate those concerns.

Click here to read the full article written by Dr. Maddie Deutsch, Associate Professor of Clinical Family & Community Medicine at the University of California – San Francisco (UCSF), and Medical Director for UCSF Transgender Care.

Risks

• Most people using masculinizing testosterone therapy will experience at least a small amount of acne. Some may experience more advanced acne. Often, this acne responds to typical over-the-counter treatments, but in some cases, prescription medication may be required. Acne usually peaks within the first year of treatment and then begins to improve.

• While gender-affirming hormone therapy usually improves mood, some people may experience mood swings or a worsening of anxiety, depression, or other mental health conditions due to the shifts associated with starting a second puberty. If you have any mental health conditions, you should remain in discussion with a mental health provider as you begin hormone therapy.

• Because testosterone typically causes menstruation to stop, you may have or develop an underlying fertility condition you are unaware of, which may impact your future ability to conceive and carry a pregnancy. While many transgender people have successfully given birth, long-term testosterone use may impact egg quality and quantity— especially for those over age 35, who may have struggled to achieve a pregnancy even without hormone therapy.

Rare Risks

• If a testosterone dose is too high for the body’s metabolism, a high hematocrit count (thickening of the blood) can result. This can cause a stroke, heart attack, or other serious conditions. This can be prevented through blood tests to monitor blood and hormone levels, ensuring appropriate dosage.

• As with anyone with a uterus, you may still experience issues with reproductive organs, such as fibroids, blocked fallopian tubes, or an imbalance in the uterine lining. The likelihood of these challenges is not increased by testosterone use, but be sure to report any return of bleeding or spotting to your provider, who may request an ultrasound or other tests. Missing a dose or changing your dose can sometimes result in bleeding or spotting.

• For those who have their ovaries removed, osteoporosis can occur if testosterone levels are too high. Thus, it is important to remain on at least a low dose of hormones post-op until at least age 50.

• Anecdotal evidence suggests that some medical conditions, such as autoimmune conditions (which can sometimes improve or worsen with hormone shifts) and migraines (which often have a hormonal component), may be impacted by gender-affirming hormone therapy, though research is lacking. Ask your medical provider if you have further questions about the risks, health monitoring needs, and other long-term considerations when taking hormone therapy.

Reassurances

• Overall, cisgender men have higher rates of cholesterol-related disorders and heart disease than cisgender women. However, the research on the risk of heart disease and strokes in transgender men suggests that risk does not increase once testosterone is begun. The risk of other medical conditions, such as diabetes, may be slightly increased by testosterone therapy, but actual research supporting these claims is limited.

• It does not appear that testosterone increases the risk of cancer in the uterus, ovaries, or breasts. Because not all breast tissue is removed during masculinizing chest surgery, otherwise known as top surgery, there is a theoretical risk that breast cancer could develop in the remaining tissue, but these rates are certainly lower than breast cancer risks in cisgender women.

• There is no evidence that testosterone therapy plays any role in HPV infection or cervical cancer. Cervical cancer is caused by an infection with the human papillomavirus, or HPV (which is transmitted sexually).

• Fortunately, since you do not have a prostate, you have no risk of prostate cancer, and there is no need to screen for this condition.

• Some of the effects of testosterone hormone therapy are reversible if you stop taking it. The degree to which they can be reversed depends on how long you have taken testosterone. In general, clitoral growth, facial hair growth, voice changes, and male-pattern baldness are not reversible.