The effect of androgenic and anabolic steroids on sebaceous gland activity and the composition of sebum was studied in power athletes. The subject self-administered large doses of androgenic and anabolic hormones during a 12-week-period of strength training. After 4 weeks of administration of hormones the sebum excretion rate increased significantly (p = 0.002) and it remained high throughout the period of exogenous steroid use. The amounts of cholesterol were significantly increased during that period. There were no differences in the amounts of the following lipid groups; free fatty acids, squalen, triglycerides, wax esters, diglycerides and paraffins. It was concluded that large doses of androgenic and anabolic steroids lead to an increase in sebum output in healthy young adult males.