bioidentical hormone replacement therapy

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"Bioidentical" hormone replacement therapy (BHRT) is the use of supplemental doses of steroid hormones with a chemical structure identical to endogenous human hormones (hormones naturally produced in the human body). Generally BHRT is prescribed to relieve the symptoms of menopause, though more recent therapies promise anti-aging effects and possible deferral of the diseases of aging. BHRT differs from conventional hormone replacement therapy, which by definition uses animal or synthetic hormones whose structures are similar or identical to those produced in the human body.

In early 2008 U.S. Food and Drug Administration (FDA) sent letters warning seven pharmacies that the claims they make about the safety and effectiveness of the BHRT products they sold are unsupported by medical evidence, and are considered false and misleading by the agency.[1] The FDA expressed concern that unfounded claims made about BHRT mislead women and health care professionals. Contents [hide] 1 Overview 2 Action 3 Potential advantages 4 Basics 5 Wiley Protocol 6 Footnotes 7 References 8 External links //

Overview

The term "bioidentical" denotes hormones that are chemically synthesized so as to be identical to the endogenous hormones of the human body: estradiol, estrone, estriol, progesterone, and testosterone. The disadvantage of this strategy (and the subsequent necessity of synthetic hormones in medical practice) is that none of the endogenous hormones have sufficient bioavailability when taken in the form of a tablet. Only 17-hydroxylated steroids remain intact following the hepatic first pass effect when administered orally. The molecular structures of bioidentical hormones are not patentable because patents can only be obtained for novel items, not pre-existing natural substances. Such hormones have become commercially profitable in some cases, particularly when it has been possible to patent some other aspect of their production such as their mechanism of delivery (such as the matrix delivery system of the estradiol patch). Trials to conclusively establish the apparent advantages of bioidentical hormones have not been conducted. It is doubtful such trials will ever be conducted unless through governments or the proponents of this therapy.

Action

Non-bioidentical synthetic progesterone analogues (called progestins) have actions similar or identical to the hormone progesterone, but progestins are a suspected human carcinogen.[2] Estrogens in general have been declared to be known carcinogens.[3] Bioidentical hormone replacement therapy has received considerable attention since the results of the Women's Health Initiative were published, which suggested Premarin and progestins had significant cancer and clot-inducing properties. When these results were publicised, the use