Last checked September 2026 against 31 sources · Editorial policy
Bioidentical hormone replacement therapy (BHRT)
Bioidentical hormone replacement therapy uses hormones with exactly the same chemical structure as the ones your body makes. FDA-approved bioidentical HRT already exists: estradiol patches, gels, sprays and tablets, and micronized progesterone. Custom-compounded 'BHRT' creams, troches and pellets are different: they aren't FDA-approved, their doses aren't standardized, and the National Academies found no rigorous evidence of their safety or effectiveness.
Body-identical estradiol and micronized progesterone are regulated and prescribed. Compounded 'bioidentical' creams and pellets aren't tested the same way.
Bioidentical hormones: expectation vs reality
What people often expect
“Bioidentical means natural and safer, and it's only available from specialist compounding clinics”
What the evidence shows
Regulated bioidentical HRT is standard and widely prescribed. Compounded versions are marketed as natural and safer, but a 2020 National Academies review requested by the FDA found only low-quality evidence and called their widespread use a public health concern. In a US survey, 86% of women didn't know compounded hormones aren't FDA-approved, and up to 2.5 million women may use them each year.
Bioidentical hormone replacement therapy explained
What is bioidentical hormone therapy?
Bioidentical hormones are identical, molecule for molecule, to the ones made by your ovaries: estradiol, progesterone and, less often, testosterone. Estradiol in patches, gels, sprays and tablets is bioidentical, and so is micronized progesterone, which is made from a plant starting material and is chemically identical to human progesterone. The term doesn't tell you whether a product is regulated, only what molecule it contains.
Learn more →FDA-approved bioidentical hormones
Many approved products are bioidentical: estradiol patches such as Climara, Vivelle-Dot and Minivelle; gels such as EstroGel and Divigel; the Evamist spray; estradiol tablets; and Prometrium, micronized progesterone in 100 mg and 200 mg capsules. Bijuva combines estradiol and progesterone in one evening capsule. These come with tested doses, manufacturing standards and a label listing benefits and risks. Many are available as generics.
What compounded BHRT is
Compounded bioidentical hormone therapy is mixed by a pharmacy to a prescriber's custom recipe, as creams, troches, capsules or pellets, and can include estradiol, estrone, estriol, DHEA and testosterone. These products don't go through FDA approval, so there's no testing that each batch contains the stated dose or that the dose protects the uterus. There's also limited federal and state oversight of their quality.
What the evidence says about compounded BHRT
The National Academies reviewed compounded bioidentical hormones for the FDA and in 2020 found a lack of rigorous evidence of safety and effectiveness from well-designed studies. Most information came from anecdotal claims, patient reports and prescriber testimonies. Menopause experts recommend reserving compounded hormones for women with allergies to ingredients in approved products or who need a dose or form that isn't available.
Are bioidentical hormones safer than synthetic HRT?
Not automatically. Risk depends mostly on the route, the dose and when you start. Transdermal estradiol, which is bioidentical, carries no extra clot risk, while oral estradiol does. Micronized progesterone may carry less risk for clots and breast cancer than some synthetic progestogens, but British menopause guidance says the evidence for breast cancer isn't strong. Compounded versions haven't been shown to be safer at all.
Learn more →BHRT pellets
Hormone pellets are implanted under the skin and release hormones for months. In a US clinic study, 57.6% of women on pellet therapy had side effects compared with 14.8% on FDA-approved HRT, and 55.3% of those with a uterus had abnormal bleeding, compared with 15.2%. Peak estradiol averaged 237.70 pg/mL on pellets, and some women had levels above 1,000 pg/mL, far above normal.
Learn more →Saliva and hormone-level testing for BHRT
Compounding clinics often adjust doses to blood or saliva hormone levels. Menopause guidance says blood tests to measure hormone levels are rarely needed and aren't helpful for adjusting HRT: doses are set by how well symptoms are controlled and by side effects. In one survey, 21% of women using hormone therapy said it had been personalized based on hormone levels.
Natural HRT and plant-based alternatives
Herbal and plant-based products sold as natural HRT aren't hormones and don't replace estrogen. In a meta-analysis, red clover didn't reduce hot flashes and soy results were mixed, and The North American Menopause Society doesn't recommend supplements or herbal remedies. Supplements aren't FDA-approved to treat any condition. If natural to you means identical to your own hormones, approved estradiol and progesterone already are.
Learn more →Testosterone in compounded BHRT
Many compounded BHRT regimens and pellets include testosterone. There's no FDA-approved testosterone product for women, so compounded creams or reduced doses of male products are off-label. Testosterone has evidence only for low sexual desire after menopause, at doses within the normal premenopausal range. Injections and pellets push testosterone above normal levels and aren't recommended.
Learn more →Bioidentical hormone therapy by the numbers
From the studies on this page
of women surveyed didn't know compounded hormones aren't FDA-approved
86%
had side effects on hormone pellets vs FDA-approved HRT in one clinic study
57.6% vs 14.8%
of hormone therapy prescriptions may be compounded, by one estimate
28% to 68%
2.5 million
Use estimates come from surveys extrapolated to the US population, so they're approximate.
Bioidentical vs compounded vs synthetic HRT compared
FDA-approved bioidentical HRT
Good for
Estradiol patches, gels, spray and tablets, and micronized progesterone. Chemically identical to your own hormones, with tested doses, manufacturing standards and a full label. Many are available as generics.Watch
Same risks and benefits as any HRT, depending on route and timing. Prometrium contains peanut oil.Compounded BHRT creams, troches and capsules
Good for
Can be made in doses or forms not available commercially, which helps a few women with allergies to ingredients in approved products.Watch
Not FDA-approved, no standardized dosing, and no evidence of better safety. Uterine protection from compounded progesterone creams isn't established.Compounded hormone pellets
Learn more →Good for
Release hormones for months without daily dosing.Watch
Can't be removed or adjusted once inserted, and caused far more side effects and very high hormone levels than approved HRT in a clinic study.Conventional non-bioidentical HRT
Learn more →Good for
Conjugated estrogens and synthetic progestogens such as medroxyprogesterone and norethindrone are effective and FDA-approved.Watch
Oral conjugated estrogens carried a higher clot risk than oral estradiol in observational studies.Herbal 'natural HRT' supplements
Learn more →Good for
Available without a prescription.Watch
Not hormones, not FDA-approved to treat anything, and not recommended for hot flashes by The North American Menopause Society.
How to choose safe bioidentical hormone therapy
- Ask whether the product is FDA-approved. Approved bioidentical estradiol and progesterone exist in most forms.
- Be wary of claims that compounded hormones are safer or more natural; the National Academies found no rigorous evidence for them.
- If you have a uterus, make sure your progestogen dose is proven to protect it, such as micronized progesterone 100 mg daily or 200 mg for 12 days a month.
- Don't rely on saliva or repeated blood hormone tests to set doses; symptom control is the guide.
- Avoid long-acting pellets as a first choice; they can't be adjusted if side effects appear.
- Ask your plan whether a compounded product is covered before paying for it; approved estradiol and progesterone are standard prescription drugs.
When to talk to a doctor about BHRT
Unexpected or heavy bleeding on BHRT
See a doctor. Bleeding on compounded hormones can mean the uterus isn't adequately protected.
More →Acne or new facial or body hair on testosterone pellets or cream
Tell your doctor. Testosterone therapy is linked with acne and hair growth, and pellets can push levels far above normal.
Urgent: Pain or swelling in one leg, or chest pain with breathlessness
Leg symptoms: call a doctor now. Chest pain or breathlessness: call 911.
Bioidentical hormones: questions women ask
What is BHRT for women?
BHRT, bioidentical (also written bio-identical) hormone replacement therapy, uses hormones chemically identical to your own, mainly estradiol and progesterone. It can mean FDA-approved products, which are standard HRT, or custom-compounded creams and pellets, which aren’t FDA-approved. The difference is testing, dose accuracy and oversight.
Is BHRT safe?
FDA-approved bioidentical HRT has the same safety profile as other HRT: favorable for most women under 60. Compounded BHRT hasn't been properly tested; the National Academies found no rigorous evidence of its safety or effectiveness, and pellets caused far more side effects than approved HRT in one study.
Bioidentical vs synthetic hormone replacement: which is better?
Neither is automatically better. Route and timing matter more: transdermal estradiol doesn't raise clot risk, and starting before 60 is favorable. Micronized progesterone may carry lower risks than some synthetic progestogens, but the evidence isn't strong.
Does BHRT work?
FDA-approved bioidentical estradiol works: systemic estrogen cuts hot flashes by about 75%. Compounded BHRT hasn't been tested in well-designed trials, so its effectiveness is uncertain, especially at the doses in custom mixes. If you want bioidentical hormones with proven effects, ask for FDA-approved estradiol and micronized progesterone.
Is bioidentical hormone therapy good for perimenopause?
Approved estradiol with micronized progesterone is a common and effective choice in perimenopause, often in a sequential regimen with a monthly bleed. It isn't a contraceptive, so you'll still need contraception. Micronized progesterone 200 mg for 12 days a month is a typical sequential regimen.
Related →Can bioidentical hormones help hair loss?
Estrogen affects the hair cycle, and falling estrogen at menopause is linked with thinning, but evidence that HRT regrows hair is limited. There's no evidence that compounded hormones work better than approved estradiol for hair, and testosterone can cause unwanted hair growth elsewhere.
Related →Is BHRT covered by insurance?
FDA-approved bioidentical products, such as generic estradiol and micronized progesterone, are standard prescriptions. Compounded BHRT and pellets aren't FDA-approved products, so check with your plan before paying for them. Ask for the price up front, since custom products and pellet procedures can be paid out of pocket.
Related →What are natural alternatives to HRT?
There's no natural product that replaces estrogen. Non-hormonal prescription medicines, CBT, clinical hypnosis and weight loss if you're overweight have evidence for hot flashes; herbal remedies and supplements don't. Vaginal moisturizers and lubricants help dryness without hormones.
Related →Sources
- Stuenkel CA. Compounded bioidentical hormone therapy: new recommendations from the 2020 National Academies of Sciences, Engineering, and Medicine. Menopause. 2021;28(5):576-578.
- Prescribing information: Prometrium (progesterone capsules). Acertis Pharmaceuticals, 2026. DailyMed, US National Library of Medicine.
- US Food and Drug Administration. NASEM study on the clinical utility of treating patients with compounded "bioidentical" hormone therapy.
- Pinkerton JV, Santoro N. Compounded bioidentical hormone therapy: identifying use trends and knowledge gaps among US women. Menopause. 2015;22(9):926-36.
- Prescribing information: Estradiol tablets USP. Teva Pharmaceuticals, 2024. DailyMed, US National Library of Medicine.
- Prescribing information: Climara (estradiol transdermal system). Bayer HealthCare, 2026. DailyMed, US National Library of Medicine.
- Prescribing information: Vivelle-Dot (estradiol transdermal system). Sandoz, 2023. DailyMed, US National Library of Medicine.
- Prescribing information: EstroGel (estradiol gel 0.06%). Ascend Therapeutics, 2026. DailyMed, US National Library of Medicine.
- Prescribing information: Evamist (estradiol transdermal spray). Padagis, 2024. DailyMed, US National Library of Medicine.
- Prescribing information: Bijuva (estradiol and progesterone capsules). Mayne Pharma, 2026. DailyMed, US National Library of Medicine.
- Pinkerton JV. Concerns About Compounded Bioidentical Menopausal Hormone Therapy. Cancer J. 2022;28(3):241-245.
- Vinogradova Y, Coupland C, Hippisley-Cox J. Use of hormone replacement therapy and risk of venous thromboembolism: nested case-control studies using the QResearch and CPRD databases. BMJ. 2019;364:k4810.
- Women's Health Concern / British Menopause Society. Fact sheet: HRT types, doses and regimens.
- Jiang X, Bossert A, Parthasarathy KN, et al. Safety assessment of compounded non-FDA-approved hormonal therapy versus FDA-approved hormonal therapy in treating postmenopausal women. Menopause. 2021;28(8):867-874.
- Nelson HD, Vesco KK, Haney E, et al. Nonhormonal therapies for menopausal hot flashes: systematic review and meta-analysis. JAMA. 2006;295(17):2057-71.
- The North American Menopause Society. The 2023 nonhormone therapy position statement of The North American Menopause Society. Menopause. 2023;30(6):573-590.
- US Food and Drug Administration. Dietary supplements.
- Pinkerton JV, Blackman I, Conner EA, et al. Risks of Testosterone for Postmenopausal Women. Endocrinol Metab Clin North Am. 2021;50(1):139-150.
- Davis SR, Baber R, Panay N, et al. Global Consensus Position Statement on the Use of Testosterone Therapy for Women. J Clin Endocrinol Metab. 2019;104(10):4660-4666.
- NHS. Oestrogen tablets, patches, gel and spray: side effects.
- Islam RM, Bell RJ, Green S, et al. Safety and efficacy of testosterone for women: a systematic review and meta-analysis of randomised controlled trial data. Lancet Diabetes Endocrinol. 2019;7(10):754-766.
- National 911 Program. 911.gov.
- Prescribing information: Premarin (conjugated estrogens tablets). Wyeth/Pfizer, 2026. DailyMed, US National Library of Medicine.
- Prescribing information: Prempro/Premphase (conjugated estrogens and medroxyprogesterone acetate). Wyeth/Pfizer, 2026. DailyMed, US National Library of Medicine.
- Smith NL, Blondon M, Wiggins KL, et al. Lower risk of cardiovascular events in postmenopausal women taking oral estradiol compared with oral conjugated equine estrogens. JAMA Intern Med. 2014;174(1):25-31.
- British Menopause Society. Tool for clinicians: HRT preparations and equivalent alternatives. 2024.
- The North American Menopause Society. The 2022 hormone therapy position statement of The North American Menopause Society. Menopause. 2022;29(7):767-794.
- Crandall CJ, Mehta JM, Manson JE. Management of Menopausal Symptoms: A Review. JAMA. 2023;329(5):405-420.
- NHS. About hormone replacement therapy (HRT).
- Gupta AK, Economopoulos V, Mann A, et al. Menopause and hair loss in women: Exploring the hormonal transition. Maturitas. 2025;198:108378.
- The North American Menopause Society. The 2020 genitourinary syndrome of menopause position statement of The North American Menopause Society. Menopause. 2020;27(9):976-992.
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