Anabolic steroids are synthetic derivatives of the male hormone testosterone. Increasingly, evidence suggests that the use of anabolic steroids can lead to serious health problems, such as cardiovascular and liver damage and reproductive problems. A limited number of anabolic steroids have been approved for veterinary and medical use. Medically, they are used to replace inadequate levels of testosterone. As drugs of abuse, they are used in combination with a high-protein diet and exercise program to improve athletic performance, appearance and self-image. Possible side effects include elevated blood pressure, severe acne, premature balding, and reduced sexual functioning, some of which may be irreversible.