Health: Male contraceptive shows promise in mice

A newly developed drug candidate shows the ability to reduce male fertility quickly and temporarily in mice, according to a study published this week in Nature Communications. The findings may present an advance in efforts to develop a male birth control pill.

Male contraceptives are currently limited to condoms and vasectomy. Although there have been multiple efforts to develop additional male contraceptives, these efforts have been limited by low efficacy, long pre-treatment times, or negative side effects.

Jochen Buck, Lonny Levin, and colleagues developed optimized soluble adenylyl cyclase (sAC) inhibitors that show potential as on-demand male contraceptives in mice. They found that sAC inhibitors can reduce mouse and human sperm motility, a key indicator of sperm function. Using groups of mice, the authors performed a series of proof-of-concept experiments to support the contraceptive action of sAC inhibitors. They found that while male mouse mating behaviour is normal, fertility is eliminated in the hours after drug administration. Contraceptive efficacy was found to be at 100% in the first two hours, and 91% in the first three hours. By 24 hours fertility had returned to normal levels. No negative health impacts were found when these drugs were administered continuously for six weeks. While the authors administered these drugs via injection in most experiments, they found that mouse sperm motility was also reduced by similar levels upon oral administration. They note that further research is needed to determine whether these drugs will work effectively in humans and to identify any potential side effects.