Your Questions Answered
What are bioidentical hormones and should I be taking them?
Lately many patients have been raising questions about the use of bioidentical hormones. Actress Suzanne Somers’ enthusiastic endorsement of this idea in her book The Sexy Years has spurred much of this discussion. Bioidentical hormones are a type of hormone replacement therapy used to treat menopausal symptoms. Bioidentical refers to the fact that these hormones (estradiol and progesterone) are the ones that occur naturally in a woman’s body prior to menopause. This contrasts with more commonly used hormonal supplements that are either synthetic (for example, Provera, a synthetic progesterone or Ethinyl estradiol, a synthetic estrogen) or derived from animal sources (for example, the estrogens in Premarin that are harvested from the urine of pregnant mares).
These “bioidentical” hormones have been marketed and used clinically for several years (Estrace or Estradiol and Prometrium, a natural progesterone in oil) as one form of post menopausal hormonal replacement therapy (HRT). The labeling as bioidentical stems from Ms. Somers’ book. Due to her own positive response to these drugs, she has become a powerful advocate of their use for all women. She does make some valid points. These drugs indeed are bioidentical and why not take them rather than the synthetic drugs. There is evidence that side effects commonly seen with the other drugs (for example, weight gain, bloating, and breast tenderness) are much less of a problem with their use. There is, however, a lack of evidence supporting their long-term safety vs. the other drugs. While her argument that they are natural and therefore safer is plausible, medical proof is lacking. This is simply because long-term comparative studies vs. the other hormones have not been done. Lack of evidence is not evidence of safety, and long-term safety of HRT has been the focus for the last several years (see previous questions of the month, for example, August of 2002).
Also many women feel well with few, if any, side effects on the “non bioidentical” hormones. Much of the medical research over the last 2 to 3 years has focused on ways to minimize HRT doses and therefore to minimize risks such as heart attacks, strokes, and possibly breast cancer. This contrasts to the approach promoted in Ms. Somers’ book. There the approach is to measure blood levels and to adjust hormone doses based on these results. The problem here is multifold. It is never quite explained how this is done. Hormonal levels normally found in women for both estrogen and progesterone have a very wide range. If the dose is adjusted to a specific range (and this is never quite explained) then this ignores a woman’s symptomatic response. That is, does she feel any better or are the side effects worse at that particular blood level? And if symptomatic response remains the main goal of treatment as it has traditionally been and as Ms. Somers initially advocates, then why go through the inconvenience and considerable cost of blood testing.
In regard to the second question initially posed--should I be taking these hormones--then the question really should be reviewed in the larger context of should I be taking HRT. Many women clearly feel better on HRT and there is no reason not to ask about trying natural vs. synthetic hormones. But their use should be evaluated not only in regard to symptomatic improvement but also in a larger context of risk vs. benefit. Potential benefits must be weighed against known risks.
Ms. Somers is to be applauded for her view that a woman is her own best advocate. She does however view the use of HRT as rather black and white. She states in her book that “Aging is the lack of hormones.” Aging is aging. Hormones in some women can provide marked improvement in quality of life but not all women want or need HRT and their use should be explored individually. They clearly should not be viewed as a fountain of youth.