The term “bioidentical hormone therapy” is often used to describe a medication containing estrogen, progesterone, or other hormones that are chemically exact duplicates of hormones produced by women, primarily in the ovaries. Many of these body-identical hormones are commercially available in several well-tested, Health Canada approved, brand-name prescription drugs.
Plant based hormones and bioidentical hormones. All of the hormones that change at menopause (estrogen, progesterone, testosterone), are in the category of the “sex steroids” which are derived from cholesterol. Cholesterol is essential to make the walls of the cells in our body, as well as a starting point for the body to manufacture hormones. Cholesterol is only made by animals, so we must either get it from our diet, or manufacture it in our bodies. There are no sex steroids occurring in any plant. Plants do have compounds that interact weakly with estrogen receptors (the “phytoestrogens”, found in soy and linseed). Plants also have compounds that can be chemically modified to be identical to human hormones. These synthetic hormones are what are described as bioidentical, and are the same whether in pharmaceutical or compounded preparations. The exception are “conjugated equine estrogens”, which are naturally occurring estrogens made by horses.
Concern arises with the bioidentical hormone medications that are “custom-compounded” (custom-mixed) recipes prepared by a pharmacist following an individual prescriber’s order for a specific patient. These medications do not have FDA or Health Canada approval because individually mixed recipes have not been tested to prove that the active ingredients are absorbed appropriately or provide predictable levels in blood and tissue. There is concern regarding the presence of impurities, lack of sterility, lack of efficacy, and lack of safety data of these preparations. Further, there is no scientific evidence to support the effects of these compounded medications on the body—either good or bad. All hormones work in the same way, by “turning on” hormone receptors, regardless of whether or not they are bioidentical.
The SOGC supports the 2017 North American Menopause Society statement on Bioidentical Hormone Therapy:
“Compounded bioidentical HT presents safety concerns such as minimal government regulation and monitoring, overdosing or underdosing, presence of impurities or lack of sterility, lack of scientific efficacy and safety data, and lack of a label outlining risks.”
The only circumstance where prescribers might consider using compounded HT is if women cannot tolerate a government-approved preparation, for reasons such as allergies to ingredients.
The North American Menopause Society position on bioidentical hormones.
Mayo Clinic position on bioidentical hormones.
The American College of Obstetricians and Gynecologists position on bioidentical hormones.