Regulatory bodies require pharmacies to include important safety information with conventional hormone replacement therapy (CHRT) via package inserts.
As early as 1980, the British Medical Journal (now The BMJ) recommended oral bioidentical progesterone as an option when side effects from synthetic progestogens otherwise mandated discontinuing treatment.
[2] Wright may have been the first proponent of BHT to use the term bioidentical—the word he coined to describe unpatentable, plant-derived molecules he believed were identical to human hormones.
When the Women's Health Initiative's reports on the unappreciated risks of equine estrogens were released, many prescribers of BHT used Wright's assertions (and his terminology) to proclaim the superiority of bioidentical molecules despite a lack of scientifically supported evidence.
[6] There is no single definition for the term bioidentical hormone replacement therapy; it is generally used to refer to 17β-estradiol, but other uses include plant-based or compounded estrogen products that blend estradiol with estriol and sometimes with estrone.
[13] BHT is often used to refer to a set of diagnostic, prescribing, preparation and marketing practices including compounding, saliva testing, and an emphasis on countering the effects of aging rather than relieving the symptoms of menopause.
This compounded BHT package has been promoted by Somers, Oprah Winfrey, and other proponents as safer and more effective than CHRT,[14][15][16][17][18][19][excessive citations] though there is no evidence to support these claims.
It is also promoted by some practitioners for anti-aging purposes providing benefits beyond menopausal symptom relief, such as improving quality of life, though there is little evidence to support these claims.
[2][20] Compounded preparations of bioidentical hormones usually include estriol, estrone, estradiol, testosterone, progesterone, and sometimes dehydroepiandrosterone (DHEA), either individually or combined.
[25] The editors-in-chief of the scientific journal Climacteric state that the greatest difference in function between bioidentical and synthetic hormones may be found in progesterone's behavior compared with progestin.
[27] A 2012 practice advisory published by Canadian Family Physician concluded "there is no convincing evidence that bioidentical hormones are safer or more effective than synthetic HRT".
[25] Compounding pharmacies use commercially available bulk drugs to create new formulations which differ in form or dosage from those manufactured on a large scale by pharmaceutical companies.
[29] Dosages used in BHT can be as high as ten times the oral dose provided by comparable HRT regimens; the hormones used are known to adversely impact biological markers of cardiovascular disease and may produce a substantially higher risk of heart attack or stroke.
[29] Progesterone can cause the emergence (or significant worsening) of abdominal pain, constipation, yeast infections, breast cancer, cystitis, acne, conjunctivitis, thrombotic disorders resulting in pulmonary embolus, strokes or heart attacks, epilepsy, migraine, asthma, and cardiac or renal dysfunction.
[35] A review of clinical trials studying bioidentical progesterone use found that it was ineffective in managing vasomotor symptoms of menopause, but had mild and self-limiting side effects.
[2] Other concerns include lack of evidence that samples are stable during storage and transportation, poor replication of results and considerable variation among assays.
[26] Boothby, Doering, and Kipersztok summarize the issue as being a poor effort to apply principles of pharmacokinetics to achieve individualized dosing for drugs that do not require it.
The book was criticized by a group of doctors who (though generally supportive of BHT) state that more research is required, and object to protocols mentioned in the book—because of their potential danger and the promoters' lack of qualifications.
[46] Michael Cirigliano and Judi Chervenak have stated in reviews of the literature on BHT that large-scale, peer-reviewed studies should be used to establish the safety, efficacy and beliefs about the use of bioidentical hormones.
Derzko concluded that there was weak (but promising) preliminary evidence that bioidentical hormones may present equal (or possibly lower) risks than conventional HRT; however, there was no data supporting the use of compounding.
Derzko recommended following evidence-based medicine and cited concerns over BHT by numerous medical organizations—requirements for oversight over compounding, black box warnings for all bioidentical products, and the establishment of mandatory adverse-events registry.
[26] M. Sarah Rosenthal, Director of the University of Kentucky Program for Bioethics and Patients' Rights, has stated that she believes BHT is an experimental therapy that is often prescribed by practitioners who sell the products, and are thus in an unethical position of conflict of interest.
Rosenthal has also described problematic issues with BHT including patients receiving information from popular books while lacking the scientific literacy to separate rhetoric from evidence about hormone replacement, illegitimate claims of a "big pharma" conspiracy to suppress bioidentical prescribing, the extra and unnecessary cost of the products that are often not covered by insurance plans, and the inaccurate depiction of bioidentical prescribing as "cutting edge science" rather than unproven alternative medicine.
[12] In 2002, the Women's Health Initiative study (WHI) that was designed to demonstrate additional benefits of conventional hormone therapy (study participants were given Prempro or a placebo) was terminated prematurely after preliminary data indicated small increases in the risks of breast cancer, heart attack and stroke in older women using Prempro.
[52] The U.S. Food and Drug Administration has warned several pharmacies about making unsubstantiated claims about the safety and effectiveness of compounded hormone products.
[18] The North American Menopause Society has stated that compounded bioidentical hormones have not been approved by the FDA; there is no guarantee of purity, potency, efficacy or safety, and they may contain unknown contaminants.
[13] Topical hormone preparations such as progesterone, estrogen and DHEA creams can be purchased in stores or over the internet and are not regulated by the FDA, as they are generally considered cosmetic.
[8] When prescribed by a licensed practitioner, the compounding of bioidentical hormones is controlled by the state pharmacy boards rather than the FDA,[60] and pharmacists are permitted to adjust dose and delivery method according to the prescription.
[2] In October 2005 Wyeth Pharmaceuticals, a manufacturer of both FDA-approved bioidentical and non-bioidentical HRT preparations, filed a citizen petition with the FDA asking for enforcement action against compounding pharmacies that dispensed BHT and to investigate labelling and advertising guidelines.
[18][39] The FDA stated that it did not take these regulatory actions against compounded bioidentical hormones in response to Wyeth's request, since that is not the purpose of a citizen petition.