Glossary · Treatments

Bioidentical hormones

Also called: Body-identical hormones.

Definition: Bioidentical hormones are hormones whose molecular structure is identical to those produced by the human body — primarily estradiol and progesterone in the menopause context. Bioidentical does not mean compounded; many FDA-approved estradiol and micronized progesterone products are bioidentical. It also does not automatically mean safer.

Detailed definition

The term "bioidentical" describes molecular identity to endogenous human hormones. Estradiol (E2), estrone (E1), estriol (E3), progesterone, and testosterone all exist as bioidentical pharmaceutical preparations. FDA-approved bioidentical estradiol products include Climara, Vivelle-Dot, Estrogel, Divigel, Estrace, Imvexxy, Estring, Vagifem, and others. FDA-approved bioidentical progesterone is Prometrium and its generics. Compounded preparations (Bi-est, Tri-est, custom-dosed estradiol or progesterone formulations) can also be bioidentical but are not FDA-tested for batch consistency. The marketing distinction "bioidentical = compounded = safer" is not supported by the evidence; the relevant safety question is the molecule, the dose, and the route of administration, not whether a product was compounded vs. mass-produced.

Why it matters in menopause

Many women are sold "bioidentical hormones" by compounding pharmacies as if they were a different and safer category than FDA-approved HRT. They are not categorically different — they may be the same molecule (estradiol, progesterone) at a different dose or in a different vehicle. ClearedRx prescribes both compounded and FDA-approved bioidentical preparations and explains the trade-offs clearly.

Sources

External references: Wikipedia.

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