Non hormonal male contraceptive implant lasts at least two years in trials Medical research The Guardian Breakthrough takes big step toward safe, reversible male contraception Cornell Chronicle COSO is a male contraception ultrasonic 'testicle bath' device Most male contraceptives take months to work, but a new approach stops sperm in under an hour, by blocking an enzyme they need to swim. In mice, one dose was 100% effective Most male contraceptives take months to work, but a new approach stops sperm in under an hour, by blocking an enzyme they need to swim. In mice, one dose was 100% effective Male contraceptive 'bath' device invented in Germany, wins Dyson award The Jerusalem Post