Editor's note: This is the last in a three-part series on menopausal hormones.
Put simply, bioidentical is a marketing term, first introduced into contemporary parlance by celebrities endorsing products.
The medical community has embraced this hormone adjective of necessity, owing to its popular cachet. Bioidentical means that hormones, for example estrogen and progesterone, are chemically synthesized; yes, man-made from plant sources, such that they are identical to those produced naturally in our bodies. From there, the plot in this Byzantine field thickens.
For starters, there is much confusion about compounded or so called formulated hormones. These are mixed by hand in batches by formulating pharmacists from the same plant-derived hormones used by pharmaceutical companies to produce bioidentical hormone products.
An advisory panel of the North American Menopause Society (NAMS) does not recommend use of compounded hormone therapy unless patients are allergic to products approved by the U.S. Food and Drug Administration. Check out new guidelines at http://www.menopause.org published in their journal Menopause, in March 2012. I have been a medical speaker for several drug companies that sell FDA-approved hormone therapy, because of the variety of bioidentical products and convenient dosing flexibility. These are tested for purity, potency, and efficacy, not always the case for compounded hormone therapy.
Compounded hormone mixtures may include estriol, and are sometimes injected under the skin in pellets. Experts do not recommend either of these practices because of inadequate information about safety and efficacy.
What's more, some physicians who prescribe compounded hormone therapy adjust doses based on saliva testing. The FDA concludes that this practice has no scientific basis. Instead, hormone therapy doses should be adjusted on symptom response, according to Dr. Holly Thacker, director of the Center for Specialized Women's Health at the renowned Cleveland Clinic, as published in an article on bioidentical hormone therapy in their Journal of Medicine last December. See more at http://www.clevelandclinic.org/womenshealth/ and http://www.speakingofwomenshealth.com.
Similarly, experts opine that blood levels of hormones often ordered by practitioners are of dubious clinical relevance. This practice most certainly can add significant expense.
In my practice, approximately 20% of the time I will recommend compounded hormones as part of the regimen for my patients when we lack a choice among the FDA-approved bioidentical hormones. I prescribe hormones separately, rather than mixing everything together, which allows for a greater individualization of care, a concept advised in the new NAMS guidelines. I should note that physicians commonly add progesterone to topical (across the skin) hormone therapy. The dominant thinking among experts today is that this practice does not provide sufficient protection of the uterus from cancer, due to inadequate absorption of topical progesterone.
The route of administration of hormone therapy for women can vary for both bioidentical and non-bioidentical forms. These include oral, vaginal, topical, and subcutaneous or deep injection. There is a strong rationale for avoiding oral estrogen. It is absorbed by passing through the liver, causing production of some proteins with negative health consequences. These include proteins that contribute to blood clots in the legs and elsewhere (thrombosis) and C - reactive protein, which is associated with increased cardiovascular risk, especially in women.
In summary, bioidentical hormones are man-made, synthesized from plant sources, and identical to those made in our bodies. The predominant medical literature recommends that bioidentical, FDA-approved hormones be used preferentially over compounded, and therefore, experimental, hormones. Additionally, dosing based on symptoms, not saliva testing or blood work, is advised by experts. Taking estrogen in a non-oral route, for example through the skin, may enhance safety.