The first male contraceptive pill passes its initial test, proving to be 99% successful and 100% effective.

Women have multiple contraceptive options, but men are limited to condoms and vasectomies. Now, researchers from the University of Minnesota and the University of Columbia, together with YourChoice Therapeutics, have successfully passed Phase 1 clinical trials of the male contraceptive YCT-529 . In the process, they demonstrated 99% efficacy in animals. If successful, it would be the first male contraceptive pill. It can inhibit sperm production and produce completely reversible infertility , with no dangerous side effects.

In a statement, YourChoice Therapeutics highlights that innovation in contraception has stagnated since the launch of the female contraceptive pill 65 years ago. "Since then, all new contraceptive options, except for the copper IUD, have relied on administering hormones to women to prevent pregnancy." They tout this new achievement as "a daily pill that achieves a contraceptive effect greater than that of condoms." They also emphasize that " preclinical studies have shown that YCT-529 was as effective as or better than the female contraceptive pill."

This step toward a new male option has been published in the journal Nature Communications Medicine . Its authors state that "currently, there is no oral contraceptive available for men to prevent pregnancy... YCT-529 is a non-hormonal male contraceptive that could be a potential drug for pregnancy prevention."

YCT-529 works by interfering with vitamin A signaling, which is necessary for sperm production and fertility. It temporarily disrupts sperm development without any hormonal effects, such as on testosterone production. This mechanism was discovered in the 1930s, and numerous published studies have since validated this pathway for scientists.

After four weeks of administration, 99% of the male mice became sterile. Furthermore, no side effects were detected, and the rodents regained fertility within six weeks after discontinuing treatment.

YCT-529 was also tested in non-human primates. Within two weeks, the monkeys showed a decrease in sperm production. After discontinuing administration of the compound, it took 10 to 15 weeks for the sperm count to return to normal.

"The decline in women's reproductive rights is fueling interest in male contraceptives," says Gunda Georg, developer of YCT-529, a professor of medicine at the University of Minnesota College of Pharmacy, and founding director of the Institutes for Therapeutic Discovery and Development. She adds, " Numerous published studies and surveys demonstrate that the world wants and needs more male contraceptive options. We also cannot deny that women are tired of bearing the burden of hormones ."

Goerg believes society is ready for a male contraceptive. And the next phase is to test it in humans . To that end, YourChoice reports that the Male Contraceptive Initiative (MCI) has committed to funding early research and a phase one clinical trial of YCT-529 in men. But these researchers' work already seems very promising for the development of the world's first male contraceptive pill.