Mayo Clinic Care Network Content

Bioidentical hormones: Are they safer?

No, they aren't. According to the Food and Drug Administration (FDA) and several medical specialty groups, the hormones marketed as "bioidentical" and "natural" aren't safer than hormones used in traditional hormone therapy, and there's no evidence that they're any more effective.

The term "bioidentical" means the hormones in the product are chemically identical to those your body produces. In fact, the hormones in bioidentical medications may not be any different from those in traditional hormone therapy. Several hormone therapy products approved by the FDA and prescribed by doctors or other health care providers contain bioidentical hormones.

The term "natural" means the hormones in the product come from plant or animal sources; they're not synthesized in a lab. However, many of these products still need to be commercially processed to become bioidentical. Traditional hormone therapies don't necessarily exclude natural hormones. For example, some FDA-approved products — such as Estrace, Alora, others, which contain estrogens, and Prometrium, a natural progesterone — are derived from plants.

Marketers of compounded bioidentical hormones say their products have certain advantages over traditional hormone therapy:

  • They're produced in doses and forms that differ from those in FDA-approved products. For many nonstandard combinations, you need to go through a compounding pharmacy — one that specializes in making medications customized for your individual needs. However, products from compounding pharmacies haven't been subject to the same rigorous quality assurance standards that standard commercially available hormonal preparations have to meet.
  • They're custom-made for you, based on a test of your saliva to assess your unique hormonal needs. But, unfortunately, the hormone levels in your saliva don't reflect the levels in your blood or correspond to menopause symptoms.

Some women may benefit from nonstandard doses and forms of hormones in compounded bioidentical hormone preparations, but there's currently no scientific support for an advantage of these compounds over common commercially produced preparations.