"It gives a lot of hope": a contraceptive pill for men in advanced development

American researchers are working on a contraceptive pill for men . This YCT-529 pill was developed in California by the YourChoice Therapeutic laboratory.

It works without hormones, unlike all female pills. But like for women, it's a pill you swallow every day. The tablet blocks a protein essential for sperm production in the testicles. Ejaculation still occurs, but the semen contains far fewer sperm.

Initial animal tests have been conclusive. The results were detailed by the scientific journal Nature. In mice, the pill causes infertility, with YourChoice Therapeutics boasting 99% effectiveness. In male primates, sperm production is blocked after two weeks. All this "without any adverse side effects."

The animals regain fertility after stopping the treatment." Mice become fertile again after about six weeks, while primates take 10 to 15 weeks. For humans, it should take longer. Since it takes 60 to 80 days to produce a sperm, it would take three to six months to produce sufficient sperm again.

Initial clinical trials have already been conducted on humans. Their results were presented last week. Sixteen male volunteers each received a dose of 10, 30, 90, or 180 mg of YCT-529. None of them experienced any side effects, including those on testosterone levels, heart rate, or libido. A second, larger clinical trial is due to launch soon, with daily doses for 28 and 90 days.

The laboratory aims to commercialize the pill by 2029, in four years. "It gives a lot of hope," says Gersende Marceau, a midwife at the Family Planning Association. But she remains cautious and critical of "the slow pace of research and the lack of financial investment." She cites the example of vasalgel, a gel that allegedly blocks sperm in the tubes that carry them. An idea launched more than 20 years ago, but which has never had any impact.

For the YCT-529 pill, there are still many testing phases to go, and several French specialists insist: there have been many trials of male contraceptives and just as many setbacks.

The only ones that exist today are the condom, vasectomy (cutting the tubes that carry sperm) or heavy hormonal treatments (testosterone injections). (intramuscular). Drug-based contraception currently relies almost exclusively on women.