After having been referred to me by a colleague, a woman who was interested in bioidentical hormone therapy contacted me. She told me that she had suffered a stroke while taking FemHRT. She thought that FemHRT was a form of bioidentical hormone therapy and she asked me if the hormone therapy that I offer to my patients could put her at risk of developing another stroke.

This is a concern that many women have. In the mainstream media estrogen is depicted as a hormone that causes cancer and other health problems. It is this misinformation that causes many women to shy away from seeking treatment for hormone deficiencies or imbalances.

FemHRT DOES NOT contain bioidentical hormones. It consists of norethindrone acetate and ethinyl estradiol.

What is the difference between bioidentical hormones and nonbioidentical hormones?

Bioidentical hormones are messenger chemicals that are identical to hormones that the human body makes in its hormone glands. There is no difference. They are identical in every way. They are made from ingredients of wild yams or soy beans. So they are synthetic hormones but bioidentical. Examples of bioidentical hormones are estradiol, estriol, estrone, testosterone, progesterone, pregnenolone, dehydroepiandrosterone (DHEA), growth hormone, triiodothyronine (T3), thyroxine (T4), hydrocortisone, and aldosterone. The body’s hormone glands make all of these and more and compounding pharmacies are able to make them available for therapeutic applications.

“Nonbioidentical hormones” are not produced by the human body and as such they are considered foreign to the body. Examples are norethindrone, ethinyl estradiol, hormones from other species (e.g., Premarin which contains estrogens derived from horse urine), all oral contraceptives, and most injectable hormones. It would be better to refer to these chemicals as hormone disruptors because they are not hormones. I prefer to reserve the term hormones to those messenger chemicals that are produced by the hormone glands of a human body and their synthetic counterparts (bioidentical hormones).

In 2004, the National Institutes of Health discontinued the Premarin-Provera arm of its Women’s Health Initiative study 1 year early, citing an increase in the risk of breast cancer, heart disease, blood clots, and stroke in women taking the study medications. This study did not use bioidentical estradiol, estriol, estrone, or progesterone. Instead, in the Premarin-Provera arm of the study women were given Premarin, a drug which contains non-bioidentical hormones that are derived from horse urine and Provera (medroxyprogesterone).

There is no evidence that the use of bioidentical hormones increases the risk of developing cancer when the dosage schedule follows the pattern that we see in healthy, young individuals.