DEAR DOCTOR K:

I've been hearing a lot about "bioidentical hormones." I'm curious about them, because I'd like a better way to treat my menopause symptoms. Are bioidentical hormones any safer than synthetic ones?

DEAR READER:

In the past few years, there's been growing interest in bioidentical hormones. That's because advocates promote them as safer and more effective than FDA-approved, conventional hormone therapy (HT).

Women have good reason to be interested in a new treatment option. Conventional combined hormone therapy (estrogen and progesterone) raises the risk of blood clots and breast cancer. It can increase the risk of heart disease, stroke and dementia in women older than 60 (or 10 years past menopause).

Most doctors now suggest HT only for short-term symptom relief. There are two reasons for that. First, in many women, the symptoms of menopause last only a few years. Second, the risks of HT increase the longer it is taken, and the older the woman taking it.

However, in many of my patients the symptoms of menopause last longer than a few years. So those patients would like to continue taking HT. Fortunately, there are other treatments -- non-hormone treatments -- that treat the symptoms of menopause. Still, some women want to continue using hormones and look to bioidenticals.

FDA-approved bioidentical hormones do exist. But supporters of bioidentical hormones are usually talking about a particular regimen called bioidentical hormone replacement therapy (BHRT).

The process involves identifying "deficiencies" in a woman's hormones. Then a mix of hormones is prescribed to correct the deficiencies. A compounding pharmacy fills the prescription using hormones from "natural" sources. This usually means they come from soy or Mexican yams.

The prescription includes estrogen and progesterone. But it may also include other hormones. Some possibilities are testosterone and dehydroepiandrosterone (DHEA). Adrenal hormones extracted from animal glands may also be included.

Proponents of BHRT make many claims for why they believe it's healthier than conventional HT. They say BHRT hormones aren't drugs because they are molecular copies of the hormones made by women's bodies. They say the only reason drug companies don't invest in them is because you can't patent natural substances. And they say they are safer than synthetic hormones.

None of these claims are true.

The FDA requires "black box" safety warnings for all FDA-approved hormone treatments for menopause. Unfortunately, hormones from compounding pharmacies aren't FDA-approved. So no black box warning is required. This gives the false impression that they are safer than commercially marketed drugs.

Research has shown the FDA-approved versions to be free of contamination and effective in relieving menopausal symptoms. Unfortunately, we do not know the answer to the question most of my patients ask: Do bioidentical hormones have the same risks as conventional HT, when taken for many years? If I had to bet, I would bet they do.

Until hormones from compounding pharmacies are tested by research, we don't know if they're safe. I suggest you stick with FDA-approved bioidentical hormones for now. Talk to your doctor about whether to take them for longer than a few years.

(Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: www.AskDoctorK.com.)

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