The Side Effects of Hormone Replacement Therapy

Bioidentical hormones are hot. Oprah Winfrey is already taking them to beat menopause. Suzanne Somers wrote a book about them—Ageless: The Naked Truth About Bioidentical Hormones—in which she describes how they’ve saved her from physical aging. More and more women are visiting hormone-therapy specialists and returning with enthusiastic stories. They feel young again; their hair and skin are radiant; and their libido is back to youthful levels.

All this is thanks to a small dose of estrogen, a dollop of progesterone and sometimes even a little testosterone, all bioidentical—which means they are the same as the versions naturally present in the body. They may be of organic (plant or animal) origin, but they don’t have to be. The idea doctors are promoting is that these hormones are safer than the traditional ones.

Bioidentical hormones are proven effective in combating the symptoms of menopause. The same is true of traditional hormone therapy. But bioidenticals may carry the same disadvantages. We know that traditional replacement estrogens increase the risk of breast cancer, and there is scientific evidence that the same is true for bioidentical estrogens.

We also know that women who have been exposed to higher concentrations of natural estrogen (because they are overweight, began menstruating at a young age or enter menopause later than average) are better protected against cardiovascular disease and osteoporosis. However, a Women’s Health Initiative study in which more than 16,000 American women between ages 50 and 79 took Premarin, estrogen isolated from pregnant mares, showed that this protective effect declines and even reverses dramatically the further women get past menopause. The study participants turned out to be at a higher risk for breast cancer, thrombosis, heart disease and stroke. That’s why traditional hormone replacement therapy is prescribed for a maximum of five years. After that, the benefits no longer outweigh the disadvantages. Bioidentical hormone replacement therapy may be slightly safer as a result of lower dosages and external application via the skin. Unfortunately, not enough research has been done to know.

One thing we don’t consider thoroughly enough in hormone replacement therapy is that sex hormones affect young bodies differently than older ones. Estrogens do different things in a baby’s body than in that of an adult woman (and it’s a good thing they do). Of course, for some women, menopause is years of torture. But it is vital that these women are thoroughly informed, preferably not only about the physical aspects but also the mental ones (to the degree body and mind can be separated—but that’s another story).