For decades, the topic of contraception has focused primarily on women. From pills and injections to intrauterine devices, the responsibility has fallen on them, while men have only had two options: condoms and vasectomies. But that is about to change.
A new drug called YCT-529 has generated great excitement. It is a non-hormonal male contraceptive pill that has already passed its first phase of clinical trials in humans without any serious side effects. This breakthrough could be the beginning of a new era in family planning, with greater shared responsibility between the sexes.
How does this pill work?
YCT-529 works by blocking a key protein related to vitamin A, which is essential for the male body to produce sperm. By interrupting this signal, sperm production is temporarily halted. The best part is that it does not affect testosterone levels or alter the hormonal system, so side effects such as acne, mood swings, or loss of sexual desire, which are so common with other methods, did not occur in the trials.
What science says (so far)
The first animal trials, including mice and primates, were a success. They achieved 99% effectiveness, and when treatment was stopped, fertility was fully restored. In 2024, another step forward was taken: 16 men who had already undergone vasectomies participated in phase 1 clinical trials. Why them? Because they could no longer have children, so there were no risks during this stage, which focused solely on evaluating the safety of the drug.
Different doses of the drug were tested, and the results were quite positive. No changes were recorded in heart rate, hormone levels, mood, or sexual desire. They even analyzed whether taking the pill with food affected its absorption, and although there was a slight delay, it was not significant.
What happens next?
Following these encouraging results, a second phase of the clinical trial is already underway in New Zealand. This time, 50 men are participating and will take the pill daily for 28 or 90 days, and its direct impact on sperm production will be evaluated. If all goes well, we could be closer to seeing this pill in pharmacies before the end of the decade.
Why is this breakthrough so important?
According to the World Health Organization, more than 21 million adolescents become pregnant each year in low-income countries, and many of these pregnancies are unplanned. Although many men recognize that contraception should be a shared responsibility, options for them remain limited.
The development of YCT-529 not only offers a safe and reversible alternative, but also represents a paradigm shift in how we understand family planning. If its efficacy is confirmed in the next phases, it will be the first non-hormonal male contraceptive pill on the market and could help balance the burden that has long been borne mainly by women.