The effects of anabolic steroids on body composition, blood pressure, lipid profile and liver functions were studied in male body builders who received a weekly . injection of nandrolone-decanoate (100 mg) or placebo for 8 weeks in a double blind way. In addition, 5 body builders received the same dosage of nandrolone-decanoate or placebo, in a double blind cross-over design during two 8-week periods, interspersed by 12 weeks. Anabolic steroids induced a 25-27% decrease in HDL-cholesterol, which was virtually reversed 6 weeks after cessation of drug use. In the SAD group an increase in diastolic blood pressure was observed, which returned to pre-anabolic values approximately 6 weeks after cessation of drug administration. No deleterious effects of anabolic drugs on plasma activity of liver enzymes were found. Increases in lean body mass were found in all groups, though the increase in the subjects who received anabolic steroids was superior to that in the placebo-treated subjects. The increase in lean body mass suggests increases in muscle mass.