Anabolic steroids are orally-ingested, synthetic (man-made) drugs that act like testosterone. They cause growth and development of male sexual organs, secondary sex characteristics, and increases in muscle size and strength. They are used for treating delayed puberty in boys, anemia , low muscle mass due to AIDs or HIV , breast cancer , and for replacing testosterone in men with low testosterone levels . Anabolic steroids often are abused by athletes for increasing muscle mass and performance. Non-athletes and non-competitive body builders also abuse anabolic steroids for cosmetic reasons.