At therapeutic dosages, androgen and anabolic steroids enhance neither muscle strength nor competitive performance. Endogenous androgen secretion is inhibited, and the net effect is negligible. The dosages taken by athletes and body-builders are 10-50 fold greater than the therapeutic dosages, and give rise to hyperandrogenic conditions. Although this improves endurance, strength and muscle development, at the same time a manifest hormone disturbance is developed with a variety of consequences. Abusers, who as a rule inject illicit preparations themselves, are also at risk of hepatitis and HIV.