HORMONE THERAPY EDUCATION
Bioidentical Hormone Therapy (BHT): What It Is, Who It’s For, and What to Watch For
If you’ve seen “bioidentical hormones” advertised as a natural way to feel like yourself again, you’re not alone. The tricky part is that “bioidentical” is used in two very different ways—and that difference matters.
Bioidentical hormone therapy is safest and most evidence-based when it means FDA-approved estradiol (often transdermal) and micronized progesterone, not custom-compounded creams or pellets. This is because compounded products have variable dosing and absorption, alongside limited safety data.
IN THIS ARTICLE
THE DEFINITION
What “bioidentical” actually means
“Bioidentical” simply means the hormone’s chemical structure matches what the human body makes—most commonly estradiol (an estrogen) and progesterone.
Many FDA-approved menopause treatments already use these “body-identical” hormones.
COMMON BODY-IDENTICAL HORMONES
Estradiol
An estrogen
Progesterone
A body-identical hormone used in many FDA-approved treatments
THE MOST IMPORTANT DISTINCTION
FDA-approved vs. compounded
REGULATED
FDA-approved bioidentical hormones
These are standardized products with consistent dosing and safety labeling. They include oral, transdermal, and vaginal estradiol, as well as micronized progesterone.
CUSTOM-MIXED
Compounded “bioidentical” hormones
These are made by compounding pharmacies, often as creams, troches, or pellets. Major medical organizations recommend against routine use because quality control, absorption, and dosing can vary, and strong long-term safety and effectiveness trials are lacking.
POTENTIAL BENEFITS
What symptoms can hormone therapy help?
For many women, hormone therapy is the most effective treatment for hot flashes and night sweats.
A major JAMA review reports systemic estrogen (with or without a progestogen) reduces vasomotor symptoms by approximately 75%, and oral and transdermal estrogen provide similar symptom relief.
SAFETY BASICS
The “uterus rule”
If you still have a uterus and you take systemic estrogen, you typically also need progesterone or progestogen to protect the uterine lining and lower the risk of endometrial overgrowth and cancer.
European endocrine guidance emphasizes this clearly.
Additionally, for some women (for example, those at increased clot risk), guidelines often prefer transdermal estradiol over oral estrogen.
COMPOUNDED PRODUCTS
Are compounded bioidentical hormones “safer” or “more natural”?
There is no good evidence they are safer or more effective than approved options, and there are specific concerns:
- Less oversight and standardization than FDA-approved therapy.
- Endometrial protection may be inconsistent with compounded progesterone creams or gels due to variable absorption.
- Trials and pooled RCT evidence for compounded therapies largely lack long-term outcomes, such as breast cancer and cardiovascular events. A 2022 systematic review and meta-analysis included 29 RCTs (1,808 women) and reported that clinical cardiovascular events, endometrial biopsy outcomes, and breast cancer risk were not studied, limiting what we can conclude about true long-term safety.
LONG-TERM OUTCOMES NOT STUDIED
Clinical cardiovascular events
Endometrial biopsy outcomes
Breast cancer risk
PREPARE FOR YOUR APPOINTMENT
A quick “smart questions” checklist for your clinician
“Do you mean FDA-approved estradiol/progesterone, or a compounded product?”
“Do I need progesterone for uterine protection?” (if you have a uterus)
“Would transdermal estradiol be safer for me than pills based on my risk factors?”
“What are my non-hormonal options if hormones aren’t right for me?”
BOTTOM LINE
Choose regulated, FDA-approved options when hormone therapy is appropriate.
If you’re considering “bioidentical hormones,” the evidence-based approach for most people is to choose regulated, FDA-approved body-identical estradiol with or without micronized progesterone, and avoid routine use of compounded formulations unless there is a specific medical reason.