Because anabolic steroids carry a severe health risk, they are banned by many international sports organisations. Despite the health risks, the main ingredient of anabolic steroids, testosterone, does increase muscle mass and performance. There are, however, many negative side effects. The use of anabolic steroids can lead to acne, stretch marks, male-pattern baldness and genital shrinkage. Even though there are benefits to be gained from using anabolic steroids, there are far more adverse side effects.Many athletes who use anabolic steroids can develop an addiction to them, and would rather keep using them than stop and get rid of the side-effects. Many of the side-effects will disappear after the use of the steroids has ended, but some side-effects, such as baldness, acne scars and stretch marks may be permanent.