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    Trusted by over 10K subscribers
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    Affordable pricing with no hidden fees
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    HomeMedication GuideEstradiol With Estriol safety
    Bioidentical estrogen combination — compoundedCompounded / Off-Label

    Bi-Estriol (Biest): Patient Information & Safety Notes

    Other names: biest, bi-estrogen, estradiol-estriol-combination

    Bi-estriol (or "Biest") is a compounded bioidentical estrogen preparation containing estradiol and estriol in varying ratios. It is used in compounded hormone replacement therapy. Neither estriol alone nor the Biest combination is FDA-approved as a standardized drug product.

    NOT FDA-approved as a standardized combination product. FDA-approved single-agent estradiol products exist (e.g., Estrace, Climara). Biest is a compounded preparation dispensed by licensed 503A pharmacies. Its specific ratios and safety profiles are not validated by FDA review.
    Reviewed by the OmniRx Health clinical team•Last reviewed Jul 4, 2026

    In plain language

    What Estradiol With Estriol is used for

    • Compounded HRT for menopausal symptom relief (hot flashes, vaginal dryness)
    • Osteoporosis prevention in postmenopausal women

    Taking this medicine

    How it is administered

    • Oral tablet
    • Oral capsule

    Read before you decide

    Risks and precautions

    Risks and warnings

    • Nausea, bloating, breast tenderness
    • Irregular spotting or periods
    • Mood changes
    • Risk of blood clot (thromboembolism) — similar to other estrogen therapies

    Who should not take it

    • Breast cancer or estrogen-receptor-positive cancers
    • History of venous thromboembolism or clotting disorder
    • Undiagnosed vaginal bleeding

    Common questions

    Patient questions

    Is Biest safer than FDA-approved estrogen?

    There is no peer-reviewed clinical evidence that compounded Biest is safer or more effective than FDA-approved estrogen products. The FDA does not approve compounded drugs for general safety, and the long-term safety of the specific Biest ratio has not been studied in large randomized trials. Discuss with a licensed provider.

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    This information is educational — not medical advice.

    This page is provided for general educational purposes and summarizes publicly available data from sources such as the U.S. Food & Drug Administration. It is not a substitute for the judgment of a licensed clinician and should not be used to start, stop, or change any medication. It may be incomplete or out of date, and individual circumstances vary. Always talk with your prescriber or pharmacist about your specific medications and health conditions. If you think you may have a medical emergency, call 911.

    Have medication questions?

    A licensed OmniRx provider can review your health history and medication list. Availability and treatment options are determined individually.

    Sources & References

    Learn more about where our data comes from and how we write and review medical content.