99% Effective: First Hormone-Free Male Birth Control Pill Enters Human Trials

YCT-529, a hormone-free male birth control pill, has shown high effectiveness in animals and is…

YCT-529, a hormone-free male birth control pill, has shown high effectiveness in animals and is now in human trials, marking a breakthrough in male contraception.

While the FDA has approved more than 20 types of contraceptives, only two options currently exist for men: condoms and vasectomies. Although about 25% of women who use contraception rely on the oral birth control pill, there is no equivalent pill available for men.

However, research from the University of Minnesota College of Pharmacy, published in Communications Medicine, has paved the way for the first hormone-free male birth control pill to reach clinical trials.

This new drug, YCT-529, is an innovative, hormone-free, orally administered contraceptive designed for men. Developed in partnership with Columbia University and YourChoice Therapeutics, YCT-529 prevents pregnancy by inhibiting sperm production.

Promising Preclinical Results

The research found:

In male mice, the drug caused infertility and was 99% effective in preventing pregnancies within four weeks of use.
In male non-human primates, the drug lowered sperm counts within two weeks of starting the drug.
Both mice and non-human primates fully regained fertility after stopping the drug. Mice regained fertility within six weeks, and non-human primates fully recovered their sperm count in 10-15 weeks.
No side effects from the drug were detected in either group.

“A safe and effective male pill will provide more options to couples for birth control,” said Gunda Georg, the corresponding author of the study and a professor in the College of Pharmacy where the drug molecule was developed. “It will allow a more equitable sharing of responsibility for family planning and provide reproductive autonomy for men.”

Clinical Trials Underway

Next steps are already underway: the research established that YCT-529 was suitable for human studies, and a phase 1 clinical trial for the drug was completed successfully in 2024 by YourChoice Therapeutics. The drug is currently undergoing safety and efficacy testing in a second clinical trial.

“This study laid the groundwork for human clinical trials of YCT-529, which are progressing efficiently,” said Nadja Mannowetz, lead author, chief science officer, and co-founder of YourChoice Therapeutics. “With the unintentional pregnancy rate at nearly 50% in the U.S. and globally, we need more contraceptive options, particularly for men.”

Reference: “Targeting the retinoid signaling pathway with YCT-529 for effective and reversible oral contraception in mice and primates” by Nadja Mannowetz, Sanny S. W. Chung, Soma Maitra, Md Abdullah Al Noman, Henry L. Wong, Narsihmulu Cheryala, Akash Bakshi, Debra J. Wolgemuth and Gunda I. Georg, 13 March 2025, Communications Medicine.
DOI: 10.1038/s43856-025-00752-7

The research was supported by the National Institutes of Health, the National Institute of Child Health and Human Development, YourChoice Therapeutics, and the Male Contraceptive Initiative.