Bioidentical Hormone Replacement: What the Term Actually Means — and the FDA-Approved List.

Bioidentical hormone replacement is hormone therapy that uses molecules chemically identical to the hormones your body produces. It is not a marketing term or a fringe concept — many FDA-approved bioidentical hormones are already on the market, including Estrace (estradiol), Vivelle-Dot (estradiol), Climara (estradiol), and Prometrium (progesterone). The confusion arises because the same phrase — bioidentical hormone replacement — is also used by clinics to describe custom-compounded preparations, which are regulated differently. Below is the clinical definition, the full list of FDA-approved bioidentical hormones, and how compounded BHRT fits in.

What bioidentical hormone replacement actually is — the clinical definition

A bioidentical hormone has the same molecular structure as the hormone produced endogenously. 17β-estradiol, micronized progesterone, and bioidentical testosterone are all examples. They are typically synthesized from plant sterols (yam or soy) and chemically converted to molecules indistinguishable from native human hormones. Bioidentical hormone replacement simply means using those molecules as menopausal HRT — via patch, gel, cream, capsule, or injection.

List of FDA-approved bioidentical hormones (2025)

This surprises many patients: a large fraction of FDA-approved HRT is already bioidentical. Below is the current list of FDA-approved bioidentical hormones commonly used in menopausal hormone therapy, grouped by hormone and delivery route. Every product on this list is FDA-approved, mass-manufactured under FDA oversight, and available with a prescription in the United States.

Estradiol oral tablets — Estrace (0.5 / 1 / 2 mg) and generics.

Estradiol transdermal patches — Vivelle-Dot, Climara, Minivelle, Alora, Estraderm.

Estradiol topical gels — EstroGel, Divigel, Elestrin.

Estradiol topical spray — Evamist.

Estradiol vaginal rings — Estring (local), Femring (systemic).

Estradiol vaginal tablets and inserts — Vagifem, Yuvafem, Imvexxy.

Estradiol vaginal cream — Estrace Vaginal Cream.

Micronized progesterone (oral) — Prometrium and generics (100 / 200 mg).

Micronized progesterone (vaginal) — Crinone, Endometrin (used primarily in fertility but bioidentical).

Testosterone (bioidentical, off-label for women) — AndroGel, Testim (dosed low for female use).

Bioidentical vs synthetic — the distinction that actually matters

The contrast that matters most in bioidentical hormone replacement is bioidentical progesterone vs synthetic progestins. Medroxyprogesterone acetate (Provera), norethindrone, and levonorgestrel are progestins — synthetic molecules that bind progesterone receptors but have additional off-target activity (some bind androgen and glucocorticoid receptors). The E3N cohort and other analyses suggest bioidentical progesterone has a more favorable breast safety profile than synthetic progestins.

Compounded bioidentical hormone replacement (cBHRT)

When a patient needs a dose between commercial increments, a combination preparation, or a delivery vehicle not commercially available, a 503A compounding pharmacy prepares a custom formulation. The active ingredients are still bioidentical; the difference is custom dosing rather than mass-produced fixed dosing. Compounded bioidentical hormones are NOT on the FDA-approved list above — they are individually prescribed preparations, not FDA-approved drug products.

The "natural" misconception in bioidentical hormone replacement

Bioidentical does not mean unregulated, plant-medicine, or supplement. Both FDA-approved bioidenticals and compounded bioidenticals use precise quantities of synthesized hormone and standard pharmaceutical excipients. Compounding is performed in FDA-registered facilities under USP Chapter <795> (non-sterile) and <797> (sterile) standards. The plant-derived starting materials are heavily processed; you are not taking yam extract.

BHRT vs HRT — is there a difference?

Clinically, “HRT” is the umbrella term for all menopausal hormone therapy. “BHRT” is most often used to refer specifically to bioidentical preparations, particularly compounded ones. Some clinics use BHRT as a marketing differentiator. The honest answer: the meaningful distinction is between bioidentical and synthetic progesterone, and between compounded and commercial preparations — not between two acronyms.

Safety profile of bioidentical HRT

For bioidentical estradiol delivered transdermally with bioidentical micronized progesterone, the available evidence — including the E3N cohort, NAMS guidance, and the British Menopause Society consensus — supports a favorable safety profile in healthy women started within the timing window. Risk is not zero (no medication is) and is individualized.

What Kindr prescribes and why

Kindr providers prescribe FDA-approved bioidentical products by default and use compounded bioidentical preparations when dose flexibility is clinically beneficial. We do not prescribe synthetic progestins outside of specific clinical scenarios.

FAQ

Clinical sources

• NAMS 2022 Hormone Therapy Position Statement
• Endocrine Society — bioidentical hormone therapy
• E3N cohort — progesterone vs progestins (Climacteric)
• FDA — Compounding & the FD&C Act (503A)
• ACOG Practice Bulletin No. 141 — Menopause Management

Related HRT guides

Explore more

• Menopause HRT service overview
• Pricing plans
• Free symptom checker
• All HRT medications
• Estrogen patch guide (Climara, Vivelle-Dot, Minivelle)
• Estrogen cream & vaginal estrogen guide
• Bioidentical hormones explained

Information on this page is for educational purposes only. Prescription medications require clinical evaluation and provider approval. Individual results vary. Not an emergency service.