Injectable Testosterone May Provide Effective Male Contraception

"For couples who can not, or prefer not to use only female-oriented contraception, options have been limited to vasectomy, condom and withdrawal," said Dr. Yi-Qun Gu, MD, of the National Research Institute for Family Planning in Beijing, China. "Our study shows a male hormonal contraceptive regimen may be a potential, novel and workable alternative."

Dr. Gu said this study is the largest multi-center, male hormonal contraceptive efficacy clinical trial of an androgen preparation in the world. Participants included 1,045 healthy fertile Chinese men aged 20-45 years. Each participant had fathered at least one child within the two years before the study and had a normal medical history. Their female partners were between 18 and 38 years of age and had normal reproductive function.

Males were injected monthly with 500 mg of a formulation of testosterone undecanoate (TU) in tea seed oil for thirty months. Results showed a cumulative contraceptive failure (pregnancy) rate of 1.1 per 100 men in the 24-month efficacy phase. No serious adverse events were reported and reproductive function returned to the normal fertile reference range in all but two participants.

"Despite the present encouraging results, the long-term safety of this hormonal male contraceptive regimen requires more extensive testing with a focus on cardiovascular, prostate and behavioral safety," said Dr. Gu.