For decades, the refrain has been the same: for men, it’s the condom or the vasectomy. Between the two? A huge medical desert. While women’s options number in the dozens, the pill for men remains the Arlesienne of modern medicine. A recently published study, however, changes the situation. Scientists at Cornell University in Ithaca, New York, have succeeded in stopping the fertility of male mice by targeting a specific stage in the production of sperm, paving the way for a simple and effective human method, without the side effects associated with taking hormones.
The secret of this advance lies in a molecule called JQ1. Rather than playing with testosterone, which can lead to mood swings or weight gain, the researchers chose to target meiosis, this key stage of reproduction during which cells divide to become gametes. By disrupting this process, sperm are simply no longer created. As Paula Cohen, director of the Center for Reproductive Sciences at Cornell, explains: “We are virtually the only group advocating the idea that contraceptive targets in the testicles are a viable means of stopping sperm production.»
The most reassuring aspect of this study, explains IFL Science, lies in its reversibility. After three weeks of treatment, the mice were sterile. But once the administration of JQ1 was stopped, the machine started up again naturally. In just six weeks, the rodents were producing healthy sperm again and were able to produce completely normal offspring. For researchers, this is proof that fertility can be paused without breaking the biological clock.
Towards patch or injection contraception?
Unlike the female pill, criticized for the wide range of side effects (from weight gain to skin problems to increased risk of cardiovascular disease), this method does not affect the endocrine system. We are not trying to deceive the brain, we intervene directly at the source, at the creation of sperm. A solution that would meet a growing demand from couples wishing to share the responsibility for contraception more equitably.
The objective is obviously not to distribute the JQ1 molecule as is, but to develop even more precise similar compounds, adapted to humans. The team is already working on three new genetic targets to block sperm production even earlier in the cycle. The idea would be to make the treatment easy to take, far from the daily constraint of taking a tablet at a fixed time. According to Paula Cohen, if future human trials confirm these results, we could see the emergence of very simple devices such as a skin patch or a quarterly injection.
Of course, there is still a long way to go. Moving from mice to humans requires years of clinical testing to ensure absolute safety. We must ensure the safety of the treatment in the long term. But the hope is there, and it is concrete. The Cornell University team also plans to launch a company dedicated to this project within two years to accelerate the development of these new molecules.
“The development of reversible, non-hormonal male contraceptives remains a critical unmet need to achieve reproductive equity”conclude the researchers. If the promises are kept, the future of male contraception will no longer be a question of “if”, but of “when”. A necessary transition to better distribute the daily burden of contraception.
