Bioidentical hormones: “Natural” doesn’t necessarily mean better

BOSTON, MA — The growing interest in a more natural approach to hormone therapy for menopausal symptoms has focused attention on bioidentical hormones. Bioidentical hormones are identical in molecular structure to the hormones women make in their bodies. Are these “natural” hormones safer or more effective than traditional hormone medications? The August issue of Harvard Women’s Health Watch explains.

Bioidentical hormone therapy is often called “natural hormone therapy” because bioidentical hormones act in the body just like the hormones women produce. However, they’re not found in nature in this form, but are synthesized from a plant chemical extracted from yams and soy. Many non-bioidentical hormones also come from “natural” plant or animal sources.

Another source of confusion comes from the mistaken notion that bioidentical hormones must be custom-mixed at a compounding pharmacy. That’s not the case. These hormones come in a range of products, including many FDA-approved prescription pills, patches, creams, and other preparations. Custom compounding is necessary only when a clinician wants to prescribe hormones in combinations, doses, or preparations not routinely available—or to order hormones not approved for women, such as testosterone and DHEA. Compounding pharmacies use some of the same ingredients that are made into FDA-approved products, but their products are not FDA-approved or regulated.

No one knows if bioidentical hormones are safer than non-bioidentical hormone drugs. Studies have shown that they can help relieve hot flashes and vaginal dryness, but few large studies have investigated the differences among the various hormones and methods of administration. More research is needed.

The bottom line: The risk of any hormonal product depends on more than how the hormone is made. The Harvard Women’s Health Watch recommends that you work closely with your doctor to determine what is right for you.