What Is Bioidential Hormone Replacement Therapy?

I’ve been reading about bioidentical hormone replacement therapy being better and safer than the birth control pill for the late-reproductive stage/early perimenopause (assuming birth control is not needed), but my gynecologist recommends the pill. What’s the difference between bioidentical hormones vs. what’s in the pill?

—Anonymous

The conversation around bioidentical hormone therapy came out of the post hoc analysis of the Women’s Health Initiative study. Briefly, the WHI used oral Prempro, which contains conjugated equine estrogens (isolated from the urine of pregnant horses) and medroxyprogesterone. At the time, experts hypothesized that some of the negative results of the study were related to the forms of estrogen and progesterone used. As a result, there was a move away from both of these forms of hormones.

It has been posited that estrogens that are identical to the estrogen our body makes would be safer. Initially, this conversation was focused around compounded creams, which are not regulated by the FDA, but for some time now, estrogen identical to that made in our bodies — called estradiol, beta-estradiol, or 17beta-estradiol — has been available in the form of patches and gels.

Combined birth control pills contain ethinyl estradiol, which is a chemically modified version of estradiol that allows it to be taken orally and enter the circulation without first being metabolized by the liver. Birth control pills suppress ovulation, so when contraception is needed, birth control pills offer both relief from perimenopausal symptoms and contraception in one package.

If you do not need contraception, typically because you or your partner have undergone a procedure such as a tubal ligation or vasectomy, there still may be reasons to choose a birth control pill over an estradiol patch or gel. For example, some women will find that a birth control pill offers better control of heavy menstrual bleeding. Depending on the type of progesterone used, some women may experience more breakthrough bleeding with estradiol patches or gels than with birth control pills.

I would encourage you to ask your doctor why they recommend a birth control pill for you. They may have specific reasons why they think it’s better … or they may not. The only way to know is to ask.