Effects of testosterone on mood, aggression, and sexual behavior in young men: A double-blind, placebo-controlled, cross-over study. Journal of Clinical Endocrinology & Metabolism

The prospects of wider application of testosterone (T) in novel indications such as male contraception have prompted re-newed interest in the investigation of nonreproductive ac-tions and safety of androgens. This study investigated poten-tial changes in mood and behavior in response to elevations in circulating T concentrations produced by the new long-acting preparation, T undecanoate (TU). Twenty-eight eugonadal men were randomized into one of two treatment groups: A1) active, receiving 1000 mg TU im followed by A2) washout, followed by A3) placebo, receiving 4 ml castor oil im; B1) placebo, 4 ml castor oil im; B2) washout followed by B3) active, receiving 1000 mg TU im. Mood, self-and partner-reported physical and verbal aggression, anger, hostility, irritability, assertiveness, self-esteem, and sexual function were assessed