Anabolic steroid

Anabolic steroid, any of a group of steroids derived from the male sex hormone testosterone. They affect growth, muscle bulk, and protein buildup, and may be used in treating patients after major surgery or severe accidents or with debilitating disease, when there may be a breakdown of body protein. However, these drugs have been abused by athletes, and for this reason they are only prescribed by hospital doctors and are not available on normal prescriptions.