What is BHRT (bioidentical hormone replacement therapy)?

BHRT, or bioidentical hormone replacement therapy, is a type of hormone therapy that uses hormones with the same molecular structure as hormones naturally made by the body. Common bioidentical hormones include estradiol, micronized progesterone, and testosterone. BHRT may be used to help with symptoms related to perimenopause, menopause, low testosterone, or other clinically meaningful hormone changes. The safest approach is individualized: the right hormone, route, dose, timing, and monitoring plan should be matched to the patient rather than treating BHRT as a one-size-fits-all solution.

Key Points

• BHRT means the hormone is structurally identical. Bioidentical hormones match the molecular structure of hormones the body naturally produces. Examples include estradiol, progesterone, and testosterone.
• BHRT is not automatically the same as compounded hormones. Some bioidentical hormones are available as commercially manufactured medications, while others may be prepared by a compounding pharmacy. “Bioidentical” describes the hormone molecule; “compounded” describes how the prescription is made.
• BHRT is commonly used for menopause symptoms. For women, BHRT may help with hot flashes, night sweats, sleep disruption, vaginal dryness, painful sex, mood changes, brain fog, and low libido when those symptoms are hormone-related.
• Men may also be evaluated for hormone replacement. For men, testosterone replacement may be considered when symptoms and properly interpreted labs support true hypogonadism. Treatment should not be based on symptoms alone or general anti-aging goals.
• Route and dose matter. Transdermal estradiol, oral progesterone, vaginal estrogen, testosterone creams, injections, and pellets can all behave differently. A risk-aware practice chooses the route and dose based on symptoms, safety, labs, and patient preferences.
• Bioidentical does not mean risk-free. BHRT can still cause side effects and may not be appropriate for people with certain cancer histories, blood clot history, unexplained bleeding, active cardiovascular disease, severe liver disease, or other risk factors. Monitoring is part of safe treatment.

Understanding BHRT

BHRT stands for bioidentical hormone replacement therapy. The term “bioidentical” means the hormone has the same chemical structure as a hormone naturally produced by the body. This is different from some older hormone therapy regimens that used hormones with different molecular structures, such as conjugated equine estrogens or certain synthetic progestins.

The most common bioidentical hormones used in clinical practice are estradiol, micronized progesterone, and testosterone. Estradiol is the primary estrogen made by the ovaries before menopause. Progesterone is produced after ovulation and has important effects on the uterine lining, sleep, mood, and the nervous system. Testosterone is produced in both men and women and plays a role in libido, muscle, energy, motivation, and overall hormone balance.

BHRT is often discussed as if it is one single treatment, but it is better understood as a category. A woman using transdermal estradiol and oral micronized progesterone is on a very different plan than a man using testosterone injections. A patient using local vaginal estrogen is also different from a patient using systemic estrogen that circulates throughout the body.

The practical question is not simply, “Is it BHRT?” The better question is: which hormone, which route, which dose, for which patient, for what goal, and with what monitoring?

How BHRT Works

BHRT works by restoring hormone support when the body is no longer producing enough of a hormone, or when hormone fluctuations are causing symptoms. In women, this most often happens during perimenopause and menopause. In men, it may happen when testosterone levels are consistently low and symptoms match the lab findings.

For women, estrogen therapy may help with hot flashes, night sweats, sleep disruption, vaginal dryness, urinary symptoms, and some quality-of-life concerns. Progesterone is usually needed when systemic estrogen is prescribed to a woman who still has a uterus, because it helps protect the uterine lining. Progesterone may also be appropriate for some women who no longer have a uterus, especially when it supports sleep, mood, or overall hormone balance, but the reason for prescribing it is different than uterine protection and should be individualized.

For vaginal dryness, painful sex, or urinary discomfort, local vaginal estrogen or other local hormone options may be used. Local therapy is different from full-body hormone therapy because systemic absorption is typically much lower.

For men, testosterone replacement may be used when symptoms such as low libido, erectile changes, fatigue, loss of muscle, poor recovery, or low motivation are paired with properly interpreted labs showing clinically meaningful low testosterone. Testosterone therapy should include monitoring because it can raise hematocrit, which is the percentage of red blood cells in the blood.

BHRT may be delivered through patches, gels, creams, capsules, tablets, injections, pellets, or vaginal preparations. Each route has tradeoffs. Some are easier to adjust, some are longer-lasting, and some may be preferred for safety reasons depending on the patient’s risk profile.

FDA-Approved Bioidentical Hormones vs Compounded BHRT

One of the biggest misunderstandings about BHRT is the idea that bioidentical always means compounded. That is not accurate. Many commercially manufactured, government-approved hormone products contain bioidentical hormones, including estradiol and micronized progesterone.

Compounded BHRT is custom-prepared by a compounding pharmacy. This can be useful when a patient needs a dose, combination, delivery form, or inactive-ingredient option that is not commercially available. For example, some patients may need a smaller dose, a different base, or a custom combination because standard products do not fit their needs.

The key distinction is that the hormone components may be FDA-approved or pharmaceutically recognized, but the final compounded prescription is not reviewed by the FDA in the same way as a commercially manufactured drug. That does not make compounded BHRT inappropriate. It means the reason for compounding should be clear, the pharmacy should be reputable, and the patient should be monitored carefully.

A balanced hormone practice may use commercially available bioidentical products when they fit and compounded BHRT when individualization is clinically useful. The decision should be based on safety, access, dose flexibility, symptom response, tolerability, and patient needs.

Who It’s For And Who Should Be Cautious

BHRT may be appropriate for women with bothersome perimenopause or menopause symptoms such as hot flashes, night sweats, poor sleep, mood changes, vaginal dryness, painful sex, urinary symptoms, brain fog, low libido, or changes in body composition. It may also be considered as part of a broader bone-health plan in properly selected patients.

For many healthy women, the benefit-risk profile of hormone therapy is often most favorable when started closer to menopause. Starting later does not automatically rule out treatment, but it requires a more careful review of cardiovascular risk, clotting history, route, dose, and alternatives.

For men, testosterone replacement may be appropriate when symptoms are consistent with low testosterone and properly interpreted labs confirm hypogonadism. It should not be prescribed simply because a man is tired, stressed, aging, or looking for performance enhancement.

People who need extra caution include those with a history of hormone-sensitive cancer, unexplained vaginal bleeding, blood clots, stroke, significant liver disease, uncontrolled high blood pressure, active cardiovascular disease, untreated sleep apnea, very high hematocrit, or complex medication histories. These situations do not always mean hormone therapy is impossible, but they change the risk-benefit discussion.

BHRT is also not a replacement for lifestyle, sleep, thyroid evaluation, metabolic health, or treatment of other medical issues. Fatigue, weight gain, mood changes, and low libido can be hormone-related, but they can also come from sleep apnea, iron deficiency, thyroid disease, insulin resistance, depression, medication effects, or chronic stress.

Risks, Side Effects, and Monitoring

BHRT can cause side effects, even though the hormones are bioidentical. Common side effects may include breast tenderness, bloating, headaches, nausea, spotting or irregular bleeding, mood changes, skin irritation from patches or creams, acne, fluid retention, sleep changes, or changes in libido. These effects are often dose- or route-related and may improve with adjustment.

Estrogen-related risks depend on route, dose, timing, duration, and personal history. Oral estrogen passes through the liver first and can affect clotting-related pathways differently than transdermal estradiol. Transdermal estradiol, such as a patch, gel, or cream, is often preferred in a risk-aware practice for patients with certain clotting, cardiovascular, migraine, or metabolic considerations.

Progesterone can also cause side effects. Some women find micronized progesterone calming or sleep-supportive, while others experience grogginess, dizziness, vivid dreams, bloating, irritability, or low mood. The dose, timing, and form of progesterone matter.

Testosterone requires careful monitoring in both men and women. In men, testosterone can raise hematocrit and may worsen untreated sleep apnea, acne, swelling, or mood symptoms in some patients. In women, too much testosterone can cause acne, oily skin, unwanted facial hair growth, scalp hair thinning, irritability, or voice changes.

Monitoring should include symptom response, side effects, blood pressure, bleeding patterns, breast or prostate considerations when relevant, medication interactions, and appropriate labs. BHRT should not be prescribed and left on autopilot. The plan should be reassessed as symptoms, health risks, medications, weight, sleep, stress, and goals change.

Safety

Seek urgent medical care right away for chest pain, shortness of breath, one-sided weakness or numbness, sudden severe headache, vision changes, fainting, calf pain or swelling, coughing up blood, or heavy vaginal bleeding. These symptoms can signal rare but serious problems such as a blood clot, stroke, pulmonary embolism, or significant bleeding.

Call your provider for non-urgent but important concerns such as persistent breast tenderness, mood changes, acne, scalp hair shedding, patch irritation, unexpected spotting, heavy or prolonged bleeding, worsening sleep, swelling, or symptoms that worsen after starting therapy. Do not adjust your dose on your own.

If you take medications for blood pressure, blood thinning, thyroid disease, diabetes, seizures, mood, or cardiovascular conditions, hormone therapy decisions should be coordinated with your prescribing clinician. Safe BHRT care depends on the full medical picture, not symptoms or lab numbers alone.

Sources and Citations

• The 2025 Menopausal Hormone Therapy Guidelines — PMC
• Use of Menopausal Hormone Therapy Beyond Age 65 Years and Its Effects on Women’s Health Outcomes by Types, Routes, and Doses — Menopause
• European Society of Endocrinology Clinical Practice Guideline for Evaluation and Management of Menopause and the Perimenopause — European Journal of Endocrinology
• Hormone Replacement Therapy — NCBI Bookshelf
• Prostate Risk and Monitoring During Testosterone Replacement Therapy — JAMA Network Open