How Safe Are Bio-Identical Hormones?

Q. I am surprised and disappointed by your answer to the lady asking for help with her hot flashes. Her doctor took her off hormones because of serious side effects, and she was suffering.
You should have recommended bio-identical hormones. They are completely free of side effects and are amazingly effective.
A. We wish there were evidence that bio-identical hormones are free of side effects. Although the Women’s Health Initiative demonstrated the dangers of PremPro, no comparable studies exist for bio-identical hormones.
Researchers have long known that the estrogen a woman makes herself has a significant impact on her risk of breast cancer (International Journal of Cancer, Oct. 15, 2010). The longer a woman has active menstrual periods, the higher the risk (International Journal of Epidemiology, online Aug. 13, 2011).
Since bio-identical hormones mimic a woman’s own hormonal production, we cannot assume that this therapy would be entirely safe. Women who would like to learn more about other ways to manage hot flashes, such as yams, Pycnogenol or vitamin E, may find our Guide to Menopause helpful.