“Bioidentical” refers to hormones that are chemically identical in molecular structure to the hormones produced naturally by the human body. The term applies specifically to estradiol (the primary form of estrogen produced by the ovaries), estriol, estrone, and progesterone — as distinguished from conjugated equine estrogen (derived from horse urine) and synthetic progestins (progesterone analogues with modified molecular structures).
The important clinical distinction — one that is frequently obscured in popular discussion of bioidentical hormones — is that many FDA-approved, rigorously studied hormone therapy products are bioidentical. Transdermal estradiol patches, gels, and sprays are bioidentical estrogen. Oral micronized progesterone (Prometrium) is bioidentical progesterone. These products are manufactured under FDA oversight with consistent dosing, quality control, and established efficacy and safety data.
The term “bioidentical” is most often used in public discourse to refer to custom-compounded hormone preparations — formulations prepared by compounding pharmacies to individual prescriptions, not manufactured under FDA oversight. These are also bioidentical in their molecular composition, but they are not FDA-regulated for safety, efficacy, or dosing consistency in the way approved products are. Understanding this distinction is the foundation of an informed conversation about bioidentical hormone therapy.
The most important distinction in the bioidentical hormone conversation is not between bioidentical and non-bioidentical molecules, but between FDA-approved products and custom-compounded preparations. Understanding this distinction determines what evidence base supports each option.
FDA-Approved Bioidentical Hormone Products
A growing range of FDA-approved hormone therapy products contain bioidentical estradiol and/or micronized progesterone. These include transdermal estradiol patches (Vivelle-Dot, Climara, Minivelle), estradiol gels (Estrogel, Divigel), estradiol sprays (Evamist), oral estradiol tablets, vaginal estradiol products (Vagifem, Yuvafem), and oral micronized progesterone (Prometrium). These products are manufactured with standardized dosing, have undergone clinical trials establishing efficacy and safety, and are subject to FDA quality oversight. They represent the bioidentical hormone options with the strongest evidence base and are the first-line bioidentical options at Lapeer Women’s Health.
Custom-Compounded Bioidentical Hormones — What They Are
Custom-compounded bioidentical hormones are prepared by compounding pharmacies to a prescriber’s individual prescription, typically combining multiple hormones in customized doses and formulations. They are marketed as “personalized” alternatives to standard hormone therapy and often use saliva testing or other hormone measurements to guide dosing. Common compounded preparations include pellet therapy (implanted subcutaneously), creams or gels in individualized formulations, and tri-estrogen combinations (Biest or Triest).
What the Evidence Shows About Compounded Preparations
Compounded bioidentical hormones are not FDA-approved for menopause treatment, and their efficacy and safety are not established by clinical trials in the way that approved products are. Compounding pharmacies are not held to the same manufacturing standards as pharmaceutical manufacturers, and dosing consistency between batches of a compounded product is not guaranteed. The FDA, the Menopause Society (formerly NAMS), and other major professional organizations have expressed concern about the lack of evidence for the safety and efficacy claims made for compounded preparations — and about the use of hormone measurement methods such as saliva testing to guide dosing in ways that are not validated for this purpose.
Pellet Therapy — A Note on the Evidence
Subcutaneous hormone pellet therapy — small pellets implanted under the skin that release estrogen or testosterone continuously over several months — is marketed as a bioidentical hormone delivery method. It is a compounded preparation and is not FDA-approved. Unlike patch or gel estradiol, pellet therapy does not allow dose adjustment after implantation — if the dose is too high or produces side effects, there is no way to remove or reduce the delivery until the pellet is depleted. The absence of FDA approval, the inability to adjust dosing once implanted, and the lack of long-term safety data are clinical considerations that Dr. Andrei discusses with patients who ask about pellet therapy.
Saliva Testing and “Hormone Level Balancing”
Saliva testing of hormone levels is often used by providers offering custom-compounded bioidentical hormones to “personalize” dosing. Saliva hormone levels are not validated for clinical decision-making in the way that serum levels are — they reflect salivary gland hormone excretion rather than circulating blood levels and vary widely with timing, technique, and individual factors. Professional societies do not recommend saliva testing for guiding hormone therapy. Symptom-based titration — adjusting treatment to achieve symptom relief at the lowest effective dose — is the evidence-based approach to hormone therapy dosing.
If you are interested in bioidentical hormone therapy, the most important first step is a clinical consultation that reviews the full range of options — including the FDA-approved bioidentical products that carry the strongest evidence base — and helps you understand exactly what you would be choosing between.
Whether considering FDA-approved or compounded preparations, these are the most important questions to have answered before starting any hormone therapy:
- Has this specific product been studied in clinical trials? What do those trials show?
- Is this product FDA-approved? If not, why is a non-approved option being recommended over an approved one?
- How will dosing be adjusted based on symptom response?
- What monitoring is planned during treatment?
Dr. Ramona D. Andrei, MD, PhD, FACOG prescribes FDA-approved bioidentical hormone products and provides a clear, evidence-based discussion of all hormone therapy options — including an honest assessment of where compounded preparations fit and where their limitations lie.
FDA-Approved Bioidentical Options First
The first-line bioidentical hormone options at Lapeer Women’s Health are FDA-approved transdermal estradiol and oral micronized progesterone — products with established evidence, consistent dosing, and regulatory oversight. For most patients seeking bioidentical hormone therapy, these products provide what is being sought without the limitations of unregulated compounded preparations.
Honest Discussion of Compounded Options
For patients specifically interested in compounded preparations or pellet therapy, Dr. Andrei provides a clear and honest discussion of the evidence, the limitations, and the clinical considerations involved — without dismissing the patient’s interest or providing a recommendation that is not evidence-based. The goal is an informed decision, not a predetermined answer.
Symptom-Based Management
Regardless of the hormone formulation selected, Dr. Andrei uses symptom-based dose titration — the validated, evidence-based approach to adjusting hormone therapy to achieve symptom control at the lowest effective dose. Follow-up is built into every hormone therapy plan to assess response and make adjustments as needed.
If you have been asking about bioidentical hormone therapy, the most useful thing a clinical evaluation can do is clarify exactly what options are available, which carry the strongest evidence, and what the real trade-offs are between FDA-approved products and custom-compounded preparations. Many women who come in asking about bioidentical hormones leave with a transdermal estradiol patch and micronized progesterone — and the understanding that they were already asking for exactly what is available in a rigorously studied form.
Dr. Ramona D. Andrei and the team at Lapeer Women’s Health are here for that conversation — at both our Lapeer and Rochester Hills offices, without a referral required.
Bioidentical Hormones
Our team at Lapeer Women’s Health will walk you through all your options honestly — at both our Lapeer and Rochester Hills offices. No referral required.
Schedule a Gynecologic VisitThe information on this page is intended for educational purposes only and does not constitute medical advice. Content reviewed by Dr. Ramona D. Andrei, MD PhD FACOG.
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Lapeer Women’s Health — Rochester Hills
2710 S Rochester Rd, Suite 2
Rochester Hills, MI 48307
Serving patients in Lapeer, Rochester Hills, and surrounding communities throughout Southeast Michigan.