To determine the effect the steroid, testosterone enanthate (TE) had on upper body strength, body composition and health. Twenty one male weight training subjects were randomly assigned in a double blind method to either a 3.5 mg(-1) x kg(-1) TE (n=11) or placebo (n=10) weight training group. The subjects were monitored during a 12 week administration phase and a subsequent 12 week follow up phase. Subjects were tested on a number of strength and size measurements, whilst having their health monitored. The results from the study revealed that the testosterone/weight training group improved significantly (p<0.05) more than the placebo/weight training group during and immediately after the administration phase on a 1 repetition maximum bench press. With regards to body composition, body weight, arm girth and rectus femoris circumference all increased significantly greater in the TE group compared to the placebo. Furthermore, the abdomen skinfold showed significant decreases in the TE group compared to the placebo group at post testing, follow up mid testing and the follow up post testing occasions. With the exception of the abdomen skinfold no within or between group differences were evident following a cycling off period of 12 weeks. Changes to baseline health indicators were reported in some subjects following testosterone usage. This included an average elevation in systolic blood pressure in all TE subjects by 10 mm Hg, a mild increase in hereditary frontal alopecia, increased muscle tightness (hamstrings and pectorals), a mild increase in libido over the first two weeks with a subsequent fall to normal, mild acne, subjective changes to personality including an increase in aggression, irritability and positive mood responses. Consequently, moderate doses of TE combined with weight training can result in short term significant changes in upper body strength and body composition, with corresponding changes to baseline health in some individuals.