From Wikipedia, the free encyclopedia

The neutrality of this article is disputed. Please see the discussion on the talk page.

"Bioidentical" hormone replacement therapy (BHRT) is the use of supplemental doses of steroid hormones with a chemical structure identical to endogenous hormones. Generally this is done with the purpose of retarding the aging process and mimicking the hormonal state of a person in their early twenties. BHRT is a modification of conventional hormone replacement therapy, which involves the use of synthetic hormones whose chemical structure different from those produced in the body.

Contents 1 'Bioidentical' 2 Potential advantages over conventional hormone replacement therapy 3 The Basics of Bioidentical Hormone Replacement Therapy 3.1 Bioidentical Estrogen 3.2 Non-Bioidentical Estrogen 4 See also 5 References

The term "bioidentical" is used by some marketers because the administered hormones are chemically synthesized and identical to the endogenous hormones of the human body: estradiol, progesterone, estriol (another natural estrogen), and testosterone are the most common. Whether these exogenous, synthetic hormones are safer or more or less effective than non-identical synthetic hormones has not been proven. All synthetic progesterone is considered a suspected human carcinogen.^[1] These synthetic substances are called progestins and are often confused with the natural hormone called progesterone.

Bioidentical hormone replacement therapy has received increasing attention since the termination of the Women's Health Initiative hormone replacement therapy clinical trials.^{[citation needed]}

• Emphasis on topical administration; avoids problems such as blood clotting that are caused by the rapid metabolism of orally administered hormones ^[2]
• Progesterone may work differently in the body than medroxyprogesterone acetate^[3]
• Emphasis on individualized doses rather than "one dose fits all" approach of conventional hormone replacement therapy^[4]
• 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^[5]

Bioidentical hormone replacement therapy is a method used to help treat the symptoms of menopause, perimenopause, and post-menopause. A common misconception is that bioidentical hormone replacement therapy is only for women. Andropause or "male menopause" can also be alleviated by biologically identical hormone replacement therapy. Although bioidentical hormones are not yet FDA approved, they are being used more and more across the world everyday. The FDA says that since they are considered to be natural, regardless of their source, they cannot be patented.

Bioidentical 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 a state of identical molecular structure, then put into a form that can be taken by the patient: cream, oral, suppository or injections.

The plants that are used to extract the hormones are soy and yams, while the animals are pigs or horses. Although these hormones become molecular identical to the ones humans produce, they cannot be considered completely natural due to the fact that they are altered in a laboratory. Below is a partial list of products that are bioidentical, and non-bioidentical:

• Micronized estradiol/Estrace-Synthesized from soy and yam.
• Estradiol/Alora-Synthetic.
• Estradiol/Climara-Synthesized from soybeans.
• Estradiol/Estraderm-Synthesized from Mexican yams.
• Estradiol/Fem Patch-Synthetic.
• Estradiol/Vivelle, Vivelle-Dot-Synthesized from Mexican yams.
• Estradiol/Estring-Synthesized from Mexican yams.

• Conjugated estrogens/Premarin-Pregnant mares' urine.
• Conjugated estrogens/Cenestin-Synthesized from soy and yams.
• Esterified estrogens (estrone, equilin)/Estra Tab-both estrone and equillin are synthesized from soy and yams.
• Esterified estrogens (estrone, equillin)/Menest-Both estrone and equillin are synthesized from soy and yams.
• Micronized estradiol/Estrace-Synthesized from soy and yams.
• Estropipate/Ogen-Synthesized from Mexican yams.
• Estropipate/Ortho-Est-Synthesized from yams.
• Ethinyl estradiol/Estinyl-Synthesized from Mexican yams.
• Estradiol cypionate/Depo-Estradiol-Synthetic.
• Estradiol valerate/Delestrogen-Synthetic.

• Hormone replacement therapy
• Prometrium
• T. S. Wiley

1. ^ Progestins as carcinogens
2. ^ Scarabin PY, Oger E, Plu-Bureau G. (2003). Estrogen and thromboembolism risk study group. Lancet, 362, 428-32.abstract
3. ^ Simoncini T, Mannella P, Fornari L, Caruso A, Willis MY, Garibaldi S, Baldacci C, Genazzani AR. (2004). Differential signal transduction of progesterone and medroxyprogesterone acetate in human endothelial cells. Endocrinology, 145, 5745-56. abstract
4. ^ Romero M. 2002. Bioidentical hormone replacement therapy. Customizing care for perimenopausal and menopausal women. Advance for Nurse Practitioners, 10, 51-2. PMID 12478948
5. ^ Bardin A, Boulle N, Lazennec G, Vignon F, Pujol P. (2004). Loss of ERbeta expression as a common step in estrogen-dependent tumor progression. Endocrine-Related Cancer, 11, 537-51. abstract

• Bioidentical Medical Dictionary
• Progestin carcinogenicity - 1987 meta-analysis regarding the carcinogenicity of medroxyprogesterone acetate
• Somers, Suzanne (2004). The sexy years: discover the hormone connection: the secret to fabulous sex, great health, and vitality for women and men. New York: Crown Publishers. ISBN 0-609-60721-9. 
• Francisco, L (2003). "Is bio-identical hormone therapy fact or fairy tale?". The Nurse practitioner 28 (7): 39-44. PMID 12861094. Retrieved on 2007-02-20.