Steroid circulates normally in both men and women, although its concentration is much higher in men. Steroid controversies in bodybuilding the development of male secondary sex characteristics, such as a deeper voice and the growth of body and facial hair. It also has effects on muscles and bones.

Performance-enhancing steroids generally work by mimicking natural testosterone. Reported effects of steroid use include increased muscle mass, strength, and lean body mass, all of which are believed to improve athletic performance.

Steroid users may become excessively aggressive or combative, a condition commonly referred to as “steroid rage.” Uncontrolled aggression leads some steroid users to clash with loved ones; sometimes, they end up in trouble with the law. Depression has also been linked to steroid use, and athletes who use steroids are more likely to attempt suicide than non-users.