Hormone replacement therapy (HRT) is used by a wide range of people, from women going through menopause to men with low testosterone to transgender individuals seeking gender-affirming care. The common thread is a hormone deficiency or imbalance that causes symptoms significant enough to treat. Despite its strong association with menopause, HRT applies to several distinct medical situations, each with its own criteria and goals.
Women in Menopause and Perimenopause
This is the largest group. About 75% of women between ages 45 and 55 experience hot flashes, sleep disruption, and mood changes as estrogen levels drop during the menopausal transition. These symptoms typically start one to three years before the final menstrual period, peak around menopause itself, and can persist for up to a decade afterward. HRT remains the most effective treatment for these vasomotor symptoms in healthy postmenopausal women who are 60 or younger and within 10 years of menopause.
Beyond hot flashes, 40% to 54% of postmenopausal women report bothersome genitourinary symptoms like vaginal dryness, painful sex, and urinary issues. These don’t always resolve on their own and often worsen over time. HRT also prevents menopause-related bone loss and reduces fracture risk, making it a reasonable option for osteoporosis prevention in early postmenopausal women.
There’s no single lab value that qualifies you for HRT. The decision is guided primarily by symptom severity. Even women with regular menstrual cycles who experience significant hot flashes may benefit from evaluation. That said, blood tests measuring estradiol, estrone, and follicle-stimulating hormone (FSH) levels help confirm where you are in the menopausal transition and can be used to monitor treatment once it starts.
Women With Early or Premature Menopause
Women whose ovaries stop functioning before age 40 have a condition called premature ovarian insufficiency (POI). When ovarian function ceases between ages 40 and 44, it’s classified as early menopause. Both groups face a longer stretch of estrogen deprivation than women who reach menopause at the typical age, which raises their risk of cardiovascular disease, osteoporosis, and cognitive decline.
For these women, HRT is recommended regardless of whether they have noticeable symptoms. The goal is to replace the hormones the body should still be producing at that age. Treatment is generally continued until at least the average age of natural menopause (around 51), at which point the risks and benefits are reassessed like they would be for any other menopausal woman. For girls and young women diagnosed with POI who haven’t completed puberty, estrogen therapy is started at low doses around age 11 and gradually increased over two to three years to support normal development.
Men With Low Testosterone
Testosterone replacement therapy (TRT) is prescribed to men diagnosed with hypogonadism, a condition where the body doesn’t produce enough testosterone. The Endocrine Society recommends making this diagnosis only when a man has both clear symptoms of testosterone deficiency and consistently low testosterone levels confirmed by repeated morning blood draws.
Symptoms of low testosterone include fatigue, reduced sex drive, erectile dysfunction, loss of muscle mass, increased body fat (especially around the midsection), depressed mood, and difficulty concentrating. These symptoms overlap with many other conditions, which is why blood confirmation is essential. Testosterone levels fluctuate throughout the day and can be affected by fasting status, illness, and medications, so a single low reading isn’t enough for a diagnosis. Once confirmed, TRT aims to restore testosterone to normal levels and relieve symptoms.
Transgender and Gender Diverse Individuals
Gender-affirming hormone therapy is a well-established medical treatment for transgender and gender diverse people. Trans women and transfeminine individuals typically take estrogen (sometimes with an androgen blocker), while trans men and transmasculine individuals take testosterone. The goal is to bring hormone levels in line with the person’s gender identity, producing physical changes that reduce gender incongruence.
Under the World Professional Association for Transgender Health (WPATH) Standards of Care, the primary requirement for adults is that gender incongruence be marked and sustained. Psychotherapy is not a prerequisite for starting treatment, though it’s available for anyone who wants it. For adolescents, the process is more staged: puberty-suppressing medications can be used once puberty has begun, with gender-affirming hormones introduced later after careful assessment of emotional and cognitive maturity. Irreversible surgical interventions are generally recommended after age 18.
Adults With Growth Hormone Deficiency
A smaller but important group includes adults whose pituitary gland doesn’t produce enough growth hormone. This typically results from a pituitary tumor, surgery on the pituitary gland, radiation therapy to the head, or a childhood deficiency that persists into adulthood. Symptoms are nonspecific: fatigue, low mood, increased belly fat, reduced muscle mass, elevated cholesterol, and a general decline in well-being and energy.
Diagnosis requires specialized stimulation testing, where doctors administer a substance that should trigger growth hormone release and then measure the response through blood draws. This testing is only recommended for people who have a plausible reason for deficiency, not as a general screening tool. Once confirmed, growth hormone replacement can improve body composition, energy levels, and cholesterol profiles.
The Timing Window for Menopausal HRT
One of the most important findings in HRT research over the past two decades is that timing matters. For women under 60 or within 10 years of menopause onset, the benefit-to-risk ratio for treating bothersome symptoms is favorable. Starting HRT during this window is associated with a reduced risk of coronary heart disease and lower all-cause mortality, based on observational data and meta-analyses from the North American Menopause Society.
Starting HRT well after this window, particularly in women over 60 or more than 10 years past menopause, shifts the balance. The cardiovascular and blood clot risks increase without the same protective benefits. This doesn’t mean older women can never use HRT, but the decision requires more careful individualized assessment.
Who Should Not Use HRT
Certain medical histories make standard estrogen-based HRT unsuitable. These include a known or suspected history of estrogen-sensitive breast cancer, other estrogen-dependent cancers (though women who’ve had a hysterectomy with no remaining disease may still be candidates), unexplained vaginal bleeding, a history of deep vein thrombosis or pulmonary embolism, blood clotting disorders like Factor V Leiden, and a history of stroke. Uncontrolled high blood pressure (above 180/110) and very high triglycerides (above 400 mg/dL) are relative contraindications that increase stroke risk.
One important exception: these contraindications generally don’t apply to low-dose vaginal estrogen products used for genitourinary symptoms, since the estrogen absorbed into the bloodstream from this route is extremely small.
Which Doctors Prescribe HRT
Multiple types of physicians prescribe hormone therapy. A survey of over 400 U.S. physicians published in the journal Menopause found that general practitioners, OB-GYNs, and wellness physicians all prescribe HRT, though their prescribing patterns differ. OB-GYNs are the most common starting point for menopausal HRT, while endocrinologists often manage more complex cases like growth hormone deficiency, testosterone replacement, and gender-affirming care. Urologists also prescribe testosterone therapy for men.
Despite its proven effectiveness, HRT use among postmenopausal women in the general U.S. population dropped sharply after the early 2000s, falling from about 27% in 1999 to under 5% in 2020. Much of that decline followed the initial release of the Women’s Health Initiative study results, which overstated risks for younger menopausal women. Medical guidelines have since been substantially revised, and many experts consider menopausal HRT underused in the women most likely to benefit from it.