Anabolic steroids include the hormone testosterone and related drugs. Anabolic steroids have many physical effects, including promoting muscle growth and increasing strength and energy. Thus, these drugs are often used illegitimately to gain a competitive edge in sports. Users are often athletes, typically football players, wrestlers, bodybuilders, or weight lifters, and most users are male.

Anabolic steroids are used medically to treat low testosterone levels (hypogonadism) and sometimes to prevent muscles from wasting away in people who are confined to bed or who have severe burns, cancer, or AIDS.