Medical Edge Newspaper Column

Are Bioidentical Hormones Better?

February 24, 2008
Dear Mayo Clinic:
I've been reading a lot about bioidentical hormones lately. What are they exactly? Are they an improvement on the usual hormone replacement therapy?

Answer:
Bioidentical hormones are chemically identical to hormones produced by the human body. They are often called natural hormones because they're made from soy and yam plant sources. However, these plant hormones do have to be chemically modified to match hormones made by the body.

Hormone therapy (commonly referred to as hormone replacement therapy) currently falls into two categories — conventional hormone therapy and compounded hormone therapy.

Conventional hormone therapy can use animal-derived, synthetic or bioidentical hormones. It is generally produced by pharmaceutical companies in standard doses and forms. Conventional hormone therapy has been reviewed and approved by the U.S. Food and Drug Administration (FDA) for safety and effectiveness and is monitored for purity and standardization.

Compounded hormone therapy generally uses bioidentical hormones, and the doses and product formulations are prepared individually for each patient by a "compounding pharmacy." Such pharmacies must adhere to the FDA and the United States Pharmacopeia (USP) compounding guidelines.

While the phrase "bioidentical" may be used differently by different people it may be helpful to keep in mind that bioidentical hormone therapy can be obtained in conventional and compounded products. Both types of hormone therapy are provided based on prescriptions from licensed medical providers.

In certain situations, customized compounded bioidentical hormones may be beneficial. Such benefits might include hormone prescriptions in individualized doses not available in conventional products and mixtures of hormones that aren't available commercially.

Recent claims that compounded bioidentical therapy is safer and more effective than conventional bioidentical therapy are unproven. In January, the FDA released a warning about compounded "bio-identical hormone replacement therapy" or "BHRT." The agency maintains that in some instances BHRT has been falsely promoted as a superior menopausal hormone therapy that has additional benefits, including the prevention and treatment of illnesses such as Alzheimer's disease, stroke and various forms of cancer. The FDA has posted a consumer update to this effect on its Web site (www.fda.gov/consumer/).

Several large clinical trials using conventional hormone therapy have shown significant benefits to women. But there are some risks associated with hormone use. In the absence of evidence to prove otherwise, we must assume that compounded bioidentical hormones carry the same risks — there's no reason to believe they're safer.

Many women benefit from use of hormones to treat symptoms and improve quality of life as they go through menopause. Postmenopausal hormones, however, are not for every woman and their use should be an individual choice for each woman with guidance by her health care provider.

— Mary Marnach, M.D., Obstetrics and Gynecology, and Richa Sood, M.D., Internal Medicine, Mayo Clinic, Rochester, Minn.