By Were Kelly
In a major leap toward gender-equitable family planning, scientists have announced that an experimental male contraceptive pill—YCT-529—has passed its initial human safety trial, potentially paving the way for the world’s first non-hormonal birth control pill for men.
The pill, developed by YourChoice Therapeutics, works by temporarily suppressing sperm production without affecting testosterone levels, offering a safe, reversible, and side-effect-free alternative to existing contraceptive methods.
According to Scientific American and New York Post reports, YCT-529 targets a specific protein called retinoic acid receptor alpha, which is essential in the sperm-making process.
By blocking this protein, the drug halts the production of sperm without impacting hormone balance—a key breakthrough, as hormonal contraceptives have historically been linked to side effects such as mood swings, reduced libido, acne, and weight gain.
To ensure safety before wider testing, the first human trial involved 16 healthy men aged between 32 and 59 who had previously undergone vasectomies. This precaution helped scientists avoid any long-term risk to fertility in case of unforeseen outcomes.
The participants were monitored for signs of toxicity and hormonal disruption. Results revealed no significant changes in heart rate, hormone levels, mood, inflammation, or sexual function.
The drug also demonstrated high bioavailability, meaning it remained effective in the body for the required duration without breaking down too quickly.
“This trial wasn’t about efficacy but about safety and tolerance,” explained Nadja Mannowetz, co-founder and chief science officer of YourChoice Therapeutics. “We wanted to confirm the drug’s safety profile before moving into trials with fertile men.”
Mannowetz emphasized the broader implications of the development, highlighting that men have long been excluded from the contraceptive equation beyond condoms and vasectomies. “Our mission is to provide men with a reliable, reversible, and side-effect-free option—and we’re finally on the path to that reality,” she said.
With the initial trial showing no safety concerns, researchers are now preparing for larger-scale studies to evaluate how effective YCT-529 is at reducing sperm counts in fertile men and preventing pregnancies in real-life settings.
If successful, the pill could revolutionize birth control and significantly shift the burden of contraception from women alone to a more shared responsibility between partners.
For now, scientists and advocates alike are calling the trial results a “historic moment” in reproductive health innovation.
