Bioidentical hormone replacement therapy (BHRT), also known as bioidentical hormone therapy or natural hormone therapy, is a poorly-defined term referring to the use of hormones that are identical, on a molecular level, with endogenous hormones in hormone replacement therapy. The term is also associated with pharmacy compounding, blood or saliva testing, efforts to reach a targeted level of hormones in the body (as established through blood or saliva testing) and unfounded claims of safety and efficacy. Specific hormones used in BHRT include estrone, estradiol, progesterone (which are available both in FDA-approved manufactured products and as pharmacy-compounded products) testosterone, dehydroepiandrosterone (both products have more limited availability and approval in Canada and the United States) and estriol (which is available in Europe but is not approved in Canada and the United States)...