ABSTRACT
In conclusion, the present study demonstrated that induced severe oligozoospermia or azoospermia by weekly testosterone enanthate injection was sufficient for male contraception. The low rates of discontinuation due to side-effects of the hormone and incidental medical conditions in this study confirms the safety and acceptability of such androgen administration found in studies with up to 18 months exposure. The long-term hazards remain uncertain and require investigation for risk. The possible long-term benefits from androgen use for bone, muscle and blood metabolism will also need to be assessed before the net risk-benefit effects of an androgen-containing regimen can be fully evaluated. In summary, the contraceptive efficacy for male contraception in this study demonstrated that weekly injections of testosterone enanthate can provide safe and effective contraceptive protection. The practicability of this approach may be improved by the use of longer-acting testosterone preparations which are under development.