Bioidentical hormones have been advertised, marketed and promoted as a risk-free panacea that is safer than standard HRT. Literature reviews by private practitioners who sell bioidentical preparations suggest benefits and advantages in the use of BHT over its conventional counterpart, but there is significant skepticism over claims made about BHT; there is no peer-reviewed evidence that compounded bioidentical hormones are safer or more effective than FDA-approved formulations or that they carry less risk. The hormones are expected to carry the same risks as their conventional counterparts, while the risks of including estriol—a hormone normally produced in large amounts only in pregnant women—have not been studied. The United States Food and Drug Administration (FDA) warned that claims about compounded BHT products are unsupported by medical evidence—unlike claims about manufactured, FDA-approved products. Bioidentical hormones have been described as a form of marketing; the chief medical editor of "Endocrine Today" called compounded BHT a "marketing concept" with no scientific backing, and the FDA warned that pharmacies use these terms to imply that the drugs are natural and have the same effects as endogenous hormones. Other claims include compounded BHT's ability to prevent or treat conditions such as heart disease, stroke, Alzheimer’s disease, endometrial and breast cancer; fewer side effects; and custom blending to uniquely address individuals. There is no credible evidence to support these claims. Bioidentical hormones and compounded BHT are expected to have the same risks and benefits as CHRT; the latter benefits from years of study and regulation, while compounded BHT has no scientific data to support claims of superior safety or efficacy. The following specific claims have been made for the efficacy of bioidentical hormones and compounded BHT, with varying evidence to support or contradict them: