testosterone supplementation can improve libido in postmenopausal women, but can also reduce levels of high-density lipoproteins. commercial sources for testosterone for women in the united states are limited and include the estrogen-testosterone mixture estratest; compounding pharmacies are the main source of testosterone-only preparations for women. a testosterone patch has been approved for use in the united kingdom and european union, but in canada and the united states there is no long-term safety data on it. dhea is an androgen precursor that lacks fda and health canada approval for use in women, and is not available in canada as a pharmaceutical preparation; it is sold as an over-the-counter drug or incorporated into compounded preparations in the united states. in the body, it can be converted into testosterone then estrogen; there are no consistent scientific findings or safety information supporting its use. high levels of dhea have been linked to breast cancer. compounding 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. custom-compounded bht is almost wholly restricted to the united states, where pharmacy compounding is governed at the state level while the fda has regulatory authority over the compounded product. some internet-based compounding pharmacies understate harm and claim benefits of compounded bht beyond what can be proven by evidence-based medicine, and many of their claims exceed those made by other bht practitioners. adverse effects bht benefits and adverse effects are expected to be the same for bioidentical and synthetic hormones. 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. there are potentially serious adverse effects and important safety information that is required to be given with fda approved hrt as package inserts; however, they are typically not given (or required) with compounded bioidentical preparations, which has caused consumers to falsely assume that bioidenticals are safer than fda-approved hormones or lack any adverse effects—one of the concerns expressed about the hormones. bht has also been associated with endometrial cancer. estrogens