Bioidentical hormone therapy: a review

In Brief Objective: The terms “natural” or “bioidentical” hormone therapy (NHT) are used to describe hormone treatment with individually compounded recipes of certain steroids in various dosage forms, including dehydroepiandrosterone, pregnenolone, testosterone, progesterone, estrone, estradiol, and estriol. Based on the results of a person's salivary hormone levels, the final composition of the compounded dosage form is individualized to that specific person. Proponents claim that NHT is better tolerated than manufactured products. This paper is intended to review the concept of NHT and to determine whether there is sufficient scientific evidence to support its use. Design: A literature search was performed in Medline using the following MeSH terms and key words: drug combinations; progestational hormones; hormone replacement therapy; endometrium; estrogen replacement therapy; climacteric; menopause; estradiol; estrogens; progesterone; drug monitoring; and drug compounding. Current Contents, International Pharmaceutical Abstracts, Cochrane Database of Systematic Reviews, Lexis Nexis, Google, Medscape, MD Consult, and clinicaltrials.gov were searched with key words. Results: There are a few observational studies and clinical trials comparing conventional hormone therapy with bioidentical hormone therapy. Studies generally lacked adequate study design, including small sample sizes and comparison of inequivalent doses, to prove safety and efficacy. Little evidence was found to support individualized hormone dosing based upon saliva hormone concentrations. Conclusion: Evidence suggests that, although individualized hormonal products may decrease some symptoms of menopause, it seems they have no proven advantage over conventional hormone therapies and their use is not supported by evidence regarding pharmacokinetics, safety, and efficacy. In response to safety concerns about hormone therapy in the lay press, women have turned increasingly to alternatives to pharmaceutical dosage forms of estrogens and/or progestogens, including hormonal substances prepared in unique, individualized dosage forms (eg, gels, sublingual tablets, suppositories). This paper reviews the scientific evidence upon which this so-called bioidentical hormone replacement is based.