An<unk> , or proandrogen, is a<unk>  (or prodrug) of an anabolic-androgenic steroid (AAS). They can be<unk> s of testosterone or of synthetic AAS, for example, nandrolone (19-nortestosterone). Dehydroepiandrosterone (DHEA), DHEA sulfate (DHEA-S), and androstenedione may all be considered proandrogens of testosterone. In the last two decades,<unk> s have also been used by bodybuilders, athletes, and nonmedical users of AAS and other hormones to refer to substances that are expected to convert to active hormones in the body. The intent is to provide the benefits of taking an AAS without the legal risks, and to achieve the hoped-for benefits or advantages without use of AAS themselves. Many of these compounds are legal to manufacture, sell, possess and ingest eliminating the legal problems associated with schedule III AAS. This also enables chemists to further their legal research and get around the law (albeit for a short time). The typical definition of<unk> " includes a steroidal molecule that has the opposite molecular structure to testosterone on either the 3a/b position or the 17b position. Testosterone has a ketone group on the 3 carbon and a hydroxyl on the 17b carbon. A steroid with modifications away from testosterone in one or both of these areas is commonly referred to as a<unk> ". These enzymatic changes occur with the body's bidirectional enzymes. On October 22, 2004, President Bush signed into law the Anabolic Steroid Control Act of 2004 (118 Stat. 1661). The bill was written to become effective in 90 days, which was January 20, 2005. This legislation places both AAS and some<unk> s on a list of controlled substances (a new type of "regulatory control"). Statutory definition of AAS: "The term 'anabolic steroid' means any drug or hormonal substance, chemically and pharmacologically related to testosterone (other than estrogens, progestins, corticosteroids and dehydroepiandrosterone)". The Act also lists substances called<unk> s, qualifying them as AAS, yet these substances were mainly included in the list due to the generalization of the definition of AAS which makes it currently impossible to synthesize any further substances linked with testosterone for the needs of athlete supplementation.
Androgen prohormone
Androgen-binding protein
Dehydroepiandrosterone sulfate
Testolactone
3β-Androstanediol
3α-Androstanediol
16α-Hydroxyestrone
Conjugated estriol