"What is hormone replacement therapy — and how do I know if it's right for me?"
Most gynecologists will encounter this common question in practice. Although many of the patients who come to you asking about hormone replacement therapy will be menopausal cisgender women, the growing number of people who are openly transgender or non-binary increases the likelihood you will encounter questions about feminizing or masculinizing hormone therapy, as well.
Although trans patients may be more likely to ask an endocrinologist or gender specialist (a specialty of licensed therapy) about hormones, gynecologists should still be prepared to answer questions about these types of hormone therapy.
What Is Hormone Replacement Therapy for Menopause?
Hormone replacement therapy for menopausal women is typically aimed at helping alleviate common symptoms, such as hot flashes, night sweats and vaginal dryness. Hormone therapy has also been linked to improved protection against bone loss and a reduced risk of fractures. However, research has also identified certain health risks of hormone replacement therapy, and it may not be the right choice for every woman.
There are two main regimens of hormone replacement therapy for menopause: estrogen-only therapy and combination therapy.
Estrogen-Only Therapy
This approach involves the daily use of supplemental estrogen alone, in the form of systemic pills, topical patches, sprays or gels. Because estrogen alone can stimulate the growth of the uterine lining and increase the risk of uterine cancer, according to StatPearls, this type of hormone replacement therapy is best reserved for women without a uterus, such as those who have undergone a hysterectomy.
Lower-dose estrogen therapy in the form of vaginal rings, creams or suppositories releases estrogen directly into the vaginal tissue. This option is typically used to treat vaginal or urinary symptoms of menopause.
Combination Therapy
For women who retain a uterus, a systemic combination of estrogen and progestin is typically prescribed. The latter helps counteract the risk of uterine cancer from estrogen alone; progestin also appears to have its own beneficial effects on hot flashes. OB/GYNs have the option to prescribe continuous combined therapy, in which estrogen and progestin are taken daily, or cyclic therapy, in which a patient takes estrogen daily and adds progestin for 10 to 14 days every month.
Risks and Contraindications
Although hormone replacement therapy can be very effective at helping alleviate menopausal symptoms, it does carry risks. The Women's Health Initiative trial of 16,608 women established as early as 2002 that combined hormone replacement therapy is associated with a small increased risk of breast cancer. More recent research has corroborated these findings. Hormone therapy has also been linked to a higher risk of ovarian cancer in postmenopausal women, according to research published in Frontiers in Endocrinology. Consider other approaches if your patient has a history of hormone-sensitive breast cancer.
Although some research found that hormone replacement therapy had a cardioprotective effect in younger women, the American College of Obstetricians and Gynecologists notes these findings were largely observational and inconclusive. Hormone replacement therapy may even raise the risk of heart attack and stroke in women who begin taking it after age 60 or after the start of menopause. Gynecologists should take a thorough personal and family history from each patient before deciding whether to prescribe hormones.
Hormone Replacement Therapy for Transgender Women
Although technically not a "replacement" therapy, hormones can be prescribed to transfeminine patients (women or nonbinary people who were assigned male at birth) as part of their gender transition. Although some transfeminine patients will choose to see an endocrinologist experienced in gender transition for hormone therapy, others may seek out a gynecologist. Even if an OB/GYN is not the physician prescribing hormones to these patients, it is important for providers to know what to expect.
What Is the Purpose of Hormone Replacement Therapy for Trans Women?
Also known as feminizing hormone therapy, this approach has two main goals: to suppress or minimize male secondary sex characteristics and to trigger the development of female secondary sex characteristics.
The effects of feminizing hormone therapy, which are often welcome for transfeminine patients, include:
- Breast development
- Redistribution of subcutaneous facial and body fat
- Reduction in body hair
- Reduction in erectile function
- Reduced sperm count
- Decreased testicular size
- Changes to libido
The most common regimen involves a combination of estrogen and an anti-androgen.
Estrogen and Anti-Androgens
In the past, oral ethinyl estrogen was recommended for feminization. However, research published in Translational Andrology and Urology notes that its use has been strongly linked to an increased risk of deep vein thrombosis. For this reason, ethinyl estrogen should be avoided. Instead, 17-beta estradiol — taken orally or applied as a transdermal patch — is now the preferred form of estrogen for transfeminine patients.
Because estrogen alone is usually not enough to suppress androgens, and the subsequent development of male secondary sex characteristics, most transfeminine patients also use an anti-androgen drug as part of their medical transition. Spironolactone is the most common anti-androgen used for this purpose. Patients taking spironolactone should be monitored with regular blood and electrolyte tests for hyperkalemia, recommends the World Professional Association for Transgender Health (WPATH).
Other options include 5-alpha reductase inhibitors, such as finasteride, although this class of medication can be associated with liver toxicity, reports LiverTox.
Hormone Replacement Therapy for Transgender Men
As with feminizing hormone therapy, masculinizing hormones do not actually replace a patient's natural hormones; instead, they are meant to aid in their gender transition by suppressing or minimizing female secondary sex characteristics and to trigger the development of male secondary sex characteristics. The most common approach here is through supplemental testosterone.
Testosterone: Treatment Options
All of the testosterone preparations prescribed in the U.S. are considered bioidentical. Testosterone is available as an intramuscular or subcutaneous injection, transdermal patch, transdermal gel, and transdermal cream. Physicians should monitor patients' levels of lipids and A1C, according to UCSF Transgender Care, as these may change with long-term use of supplemental testosterone.
The effects of testosterone therapy in transmasculine patients can include:
- Development of facial hair
- Redistribution of subcutaneous facial and body fat
- Receding hairline
- Increased muscle mass
- Deepening of voice
- Clitoral growth
- Vaginal dryness
- Cessation of menses
- Increased libido
Many of these will be welcome to patients. Some, like vaginal dryness, may require additional treatment to manage.
So, what is hormone replacement therapy? Gynecologists across the board should reference the WPATH guidelines for more details and, ultimately, to provide better care. By educating yourself about the various uses of hormone therapy for both cisgender and transgender patients, you'll be prepared to answer any questions that come your way.
