Bioidentical hormones
Also called: body-identical hormones, compounded hormones
What it means
Bioidentical (or body-identical) hormones are hormones that are structurally identical to the ones your own body makes, such as estradiol or progesterone. They can come as regulator-approved products or as custom-compounded preparations, and these are not the same thing.
Knowing the difference helps you have an informed conversation with your prescriber about hormone options that may affect bone health around menopause.
People often hear 'bioidentical' and think of something custom-made just for them, but many approved, mainstream hormone products are already body-identical. For example, a 17-beta-oestradiol patch is structurally the same molecule your ovaries produced, and micronised progesterone matches your own progesterone. These are tested, regulated, and have consistent dosing.
The concern from major medical societies isn't about body-identical hormones themselves, but about custom-compounded versions, especially pellets and creams mixed to individual prescriptions, and the practice of adjusting doses using saliva hormone testing. The issues raised are practical: doses can vary from batch to batch, there's no large-scale outcome research behind them, and safety monitoring isn't well established. Pellets carry an extra concern because once implanted, the dose can't be stopped or adjusted.
Another real safety issue is that endometrial protection, meaning protecting the uterine lining, isn't always handled consistently with compounded products, which matters for women who still have a uterus. If you're interested in body-identical hormones, regulated and approved versions exist, and any decisions about starting, changing, or choosing a hormone product belong with your prescriber.
How sure is this?
Graded Established Science: Supported by broad scientific consensus and decades of research. Read each study with its grade in mind. One study is a piece of the picture, not the whole of it.
Where the Academy teaches it
This page is the short version. The lessons teach it in full, with the context around it and a quiz to lock it in.
Questions people ask about this
Whether hormone therapy is right for your bones is a decision only you and your prescriber can make, based on your personal history — but it's worth knowing the evidence on hormones and bone is actually strong and has often been misrepresented, which is likely why your doctor is being careful. The caution usually traces back to one 2002 trial that was widely misreported; since then, the understanding has shifted considerably, especially around a woman's age and timing when therapy starts.
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Education only, not medical advice. Decisions about tests, medications and treatment belong with your own doctor. OsteoStrong does not diagnose, treat or cure any disease.
