Bio-Identical Hormones

"Bio identical" 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). On 1/10/2008 the US Food and Drug Administration sent letters warning seven pharmacy operations that the claims they make about the safety and effectiveness of their so-called "bio-identical hormone replacement therapy," or "BHRT" products are unsupported by medical evidence, and are considered false and misleading by the agency. The FDA is concerned that unfounded claims like these mislead women and health care professionals. 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 differ from those produced in the human body.

Potential Advantages:

• Emphasis on topical administration; avoids problems such as blood clotting that are caused by the rapid metabolism of orally administered hormones.
• Progesterone may work differently in the body than medroxyprogesterone acetate.
• Individualized compounded doses may be prescribed, rather than "one dose fits all" approach of conventional hormone replacement therapy.
• Inclusion of estriol may be protective against hormone-induced cancer. Unlike estradiol, estriol binds preferentially to the second estrogen receptor (ERbeta).
• ERbeta may function as a tumor suppressor. Estriol is not approved for human use by the FDA, who considers the term "bio-identical" to be non-scientific.

Patentable drugs are extensively tested. In the absence of similar testing, the potential benefits of BHRT remain unconfirmed. BHRT may present risks for breast cancer similar to those posed by conventional HRT, or the inclusion of estriol may obviate these risks. A pilot study conducted by the U.S. National Institutes of Health indicated that the risks of blood clotting and strokes that arise with Premarin and PremPro are sharply lower or nonexistent with bio identical esterified estrogens. Oral conjugated equine estrogens (Premarin) were found to be associated with increased venous thrombotic risk. In sharp contrast, the study found that users of esterified estrogen had no increase in venous thrombotic risk.

Bio identical hormone replacement therapy is used to help treat the symptoms of menopause, perimenopause, and post-menopause. Treatment with bio identical hormones is theoretically based on creating a unique cocktail of hormones for the individual patient, based on hormone deficiencies identified via saliva samples. These are often referred to as "custom-compounded" hormone products. The major benefit of this type of treatment is that doses are individualized, and the mixture of products may not be commercially available. However, although some of the estrogen and/or progestogen components are FDA approved, the mixtures themselves are not, as they have not been studied to confirm that they are absorbed appropriately or provide predictable levels in blood and tissue.

Bio identical hormones, sometimes referred to as natural hormones, are those that are molecularly identical to the hormones that are produced in the body. Hormones and steroids are taken from plants and animals and altered to be identical in molecular structure, then put into a form that can be absorbed by the body: cream, oral, suppository or injections. The plants that the hormones are extracted from are soy and yams, while the animals are pigs or horses. These hormones become molecularly identical to the ones humans produce.

The FDA recognizes pharmacy compounding of BHRT products when the product conforms to a licensed practitioners decision that an FDA-approved drug does not meet the patient's needs, but the FDA is concerned that some claims about BHRT products may be false or misleading.

Some bioidentical hormones are FDA approved. Others, such as Estriol, are not approved for human use by the FDA. Compounding pharmacies were warned by the FDA to stop using the "non-scientific" term "bio-identical" in 2008, a warning supported by The Endocrine Society and the American Association of Clinical Endocrinologists.

Individually-compounded mixtures have not been approved by the FDA, and by their very nature are not susceptible to FDA approval. Consequently, they are untested for purity, potency, efficacy or safety, and some may contain unknown contaminants. Estrogen and progesterone are available in FDA-approved forms - estradiol derived from soy or yam sources is found in some approved medications.