Anabolic steroids are hormones that facilitate building up of components of the body or the organisms that produce them.
The use of these hormones as aids to body building and athletic performance have been banned in sports for several reasons. One of these reasons is the detrimental health effects that have become apparent with their use. There is evidence that the use of anabolic steroids may actually cause a form of dependency, animal studies have shown that male and female hamsters will voluntarily self-administer testosterone and other anabolic steroids, even to the point of fatal overdose. These results have led researchers to conclude that the substances are potentially addictive, "independent of their effects on muscle mass or athletic performance".
In the United States, anabolic steroids are listed in the Schedule III of the Controlled Substance Act, along with psychoactive drugs such as ketamine and paregoric, allowing its possession only with a DEA license or prescription.