"Anabolic-androgenic steroids (AAS) are synthetically produced variants of the naturally occurring male sex hormone testosterone. “Anabolic” refers to muscle-building, and “androgenic” refers to increased male sexual characteristics. “Steroids” refers to the class of drugs. These drugs can be legally prescribed to treat conditions resulting from steroid hormone deficiency, such as delayed puberty, as well as diseases that result in loss of lean muscle mass, such as cancer and AIDS.\n\nSome people, both athletes and non-athletes, abuse AAS in an attempt to enhance performance or improve physical appearance. AAS are taken orally or injected, typically in cycles rather than continuously. “Cycling” refers to a pattern of use in which steroids are taken for periods of weeks or months, after which use is stopped for a period of time and then restarted. In addition, users often combine several different types of steroids in an attempt to maximize their effectiveness, a practice referred to as “stacking.”\n\nThe acute effects of AAS in the brain are substantially different from those of other drugs of abuse. The most important difference is that AAS are not euphorigenic, meaning they do not trigger rapid increases in the neurotransmitter dopamine, which is responsible for the “high” that often drives substance abuse."