Multicenter Contraceptive Efficacy Trial of Injectable Testosterone Undecanoate in Chinese Men

Context: Hormonal male contraceptive regimens effectively and reversibly suppress sperm production, but there are few large-scale efficacy studies. Objective: The safety, contraceptive efficacy, reversibility, and feasibility of injectable testosterone undecanoate (TU) in tea seed oil as a hormonal male contraceptive was assessed. Design: This was a multicenter, phase III, contraceptive efficacy clinical trial. Participants: A total of 1045 healthy fertile Chinese men were recruited throughout China into the study. Intervention(s): Injections of 500 mg TU were administered monthly for 30 months. A definition of severe oligozoospermia (≤1 × 106/ml) was used as a criterion of spermatogenic suppression and as the threshold for entering the contraceptive efficacy phase. Main Outcome Measure(s): The primary outcome was pregnancy rate in the partner. Other outcomes include: semen parameters, testis volumes, reproductive hormone levels, and safety laboratory tests. Results: Forty-three participants (4.8%) did no...