Bioidentical vs synthetic HRT

“Bioidentical” is one of the most used words in menopause marketing, and one of the least precise. It describes a hormone with the same chemical structure as the one your body makes. It does not tell you whether a product is FDA-approved, how it was made or whether it is safer. Plenty of FDA-approved hormone therapy is bioidentical, and plenty of what is sold as “bioidentical hormone therapy” is compounded and unapproved.

The more useful question is whether a product is FDA-approved or compounded. Here is how the three groups compare, what the evidence says and what each costs online as of October 2026.

Three groups, not two

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Estradiol is the main estrogen the ovaries make. The FDA-approved estradiol on pharmacy shelves, in tablets, patches, gels and sprays, is the same molecule. So is the progesterone in micronized progesterone capsules. If what you want is a hormone identical to your own, FDA-approved options already deliver it.

The non-bioidentical products are mostly the older ones: conjugated equine estrogens and medroxyprogesterone acetate, the pair used in the Women’s Health Initiative estrogen-plus-progestin trial. “Synthetic” is often used loosely for these.

What “compounded” means

A compounding pharmacy prepares a medication for one patient’s prescription, often a cream or troche at a custom strength. Estradiol, progesterone and testosterone are standard pharmacy ingredients, and a state-licensed 503A pharmacy can lawfully compound them for an individual prescription. Under FDA rules, though, a compounded product should not be an essential copy of an approved drug; the prescriber needs a clinical reason, such as a different strength, dosage form or ingredient.

The FDA’s guidance for telehealth companies puts the difference plainly: generic drugs are approved by the FDA before marketing, while a compounded drug is not, and compounded drugs are not reviewed by the agency for safety, effectiveness or quality before marketing. The same guidance warns companies not to describe a compounded drug as a generic version of an approved drug, as the same as one, or as FDA-approved.

Some compounded formulas have no approved equivalent at all. Estriol, the second ingredient in bi-est creams, is not in any FDA-approved US drug, so there is no approved label or safety data for it. Hormone pellets, which are implanted and cannot be removed, are another compounded form; we don’t cover them, because they require an in-office procedure.

What the evidence says

The National Academies review

The FDA asked the National Academies of Sciences, Engineering, and Medicine to review compounded bioidentical hormone therapy. Its 2020 report, The Clinical Utility of Compounded Bioidentical Hormone Therapy, found few well-designed clinical trials, and those that exist had serious methodological limits. As RAPS reported, the committee concluded that the evidence does not support the clinical utility of these products, that claims they are natural and superior were not supported, and that their use should be limited to patients who cannot use FDA-approved products. The FDA said it would review the findings and keep working to protect access for patients who need compounded drugs.

In 2017 the FDA also opened a process to list drugs that are demonstrably difficult to compound, and it has considered hormone pellets for that list. As of our October 2026 review, that list had not been finalized.

The label’s own answer on “natural”

The generic estradiol tablet label addresses the question directly in its boxed warning: “There is no evidence that the use of ‘natural’ estrogens results in a different endometrial risk profile than ‘synthetic’ estrogens at equivalent estrogen doses.” In other words, the endometrial cancer risk of estrogen alone applies to bioidentical estrogen too, compounded or not. If you have a uterus, you need a progestogen with either.

Where molecules do seem to matter

Among FDA-approved products, there is some evidence that the specific hormone and route make a difference. In a 2019 BMJ study of 80,396 UK women with blood clots and 391,494 controls, oral estradiol carried a lower clot risk than oral conjugated equine estrogens (odds ratios 0.85 for estrogen alone and 0.83 combined), and estrogen through the skin carried no increase at all. This was an observational study of approved products, not of compounded creams, so it says nothing about whether compounded hormones are safer.

Testosterone

For testosterone, the 2019 Global Consensus Position Statement, endorsed by The Endocrine Society and The North American Menopause Society among others, recommends against compounded testosterone for women because of the lack of evidence, and suggests an approved male product at a female dose instead, with blood levels monitored. See testosterone for women.

What each costs online

As of October 2026, these are the published monthly prices at online providers we compare:

Compounded creams run $46 to $149 a month, so they are not a cheaper route on their own; Musely’s and Alloy’s FDA-approved estradiol pills cost less than any compounded cream on the list. Winona labels which of its products are compounded, and Henry Meds names its creams compounded and its patch and tablets FDA-approved. Joi + Blokes says only that some of its products may be compounded. Our cost guide has the full price tables.

How to choose

• If you want bioidentical hormones, FDA-approved estradiol and micronized progesterone are bioidentical, labeled, and made to approved quality standards.
• If you’re offered a compounded cream, ask why an approved product won’t work for you, which pharmacy makes it and how the dose is checked.
• If a product contains estriol or testosterone, know that no FDA-approved US product contains estriol and none for women contains testosterone, and testosterone is a Schedule III controlled substance.
• Be wary of superiority claims. Saying a compounded product is safer or more natural than FDA-approved therapy is the kind of claim the National Academies found unsupported.
• Whatever you use, pair estrogen with a progestogen if you have a uterus.

Our compounded bioidentical hormones page covers the legal status in more detail, and the ranked list of menopause providers shows which services sell each type.

The bottom line

Bioidentical describes a molecule, not a safety record, and FDA-approved estradiol and progesterone already are bioidentical. The meaningful difference is approval: compounded hormones skip FDA review, and the National Academies found the evidence too thin to support them except for people who cannot use an approved product. As of October 2026 they also cost $46 to $149 a month online, against $35 for the lowest-priced FDA-approved estradiol pill. Start with a licensed clinician and an approved product, and treat compounding as the exception it is meant to be. More options are on the menopause hub.