YourChoice Therapeutics begins first-in-human trial for male birth control pill

December 13, 2023

YourChoice Therapeutics, Inc., a pioneer of hormone-free family planning products, began dosing male volunteers in a phase one clinical study of YCT-529, a drug candidate designed to offer the first hormone-free male birth control pill. The initial preclinical studies, funded in part by the National Institutes of Health, showed YCT-529 was 99% effective and 100% reversible with no side effects.

Data show most men and women believe contraception is a shared responsibility. However, male options are limited to withdrawal, condoms, and vasectomy, which have significant shortcomings. While a male birth control pill has been a vision for decades, current drug candidates in clinical development use hormonal agents that suppress testosterone to prevent sperm production. However, testosterone does not stop sperm production completely and ethnic variations exist. It’s also linked to serious side effects like increased risk for cardiovascular disease as well as weight gain, acne, and mood changes like aggression and decreased libido.

YCT-529 is a hormone-free birth control pill for men. As a retinoic acid receptor-alpha (RAR-alpha) inhibitor, YCT-529 prevents sperm production by blocking access to vitamin A, a well-established pathway first discovered in the 1930s when researchers found that depriving mice, rats, and monkeys of vitamin A caused infertility. Researchers validated the discovery in men and advanced their understanding in nearly 100 published papers.

YCT-529 reflects two decades of research led by its developer Gunda Georg, regents professor at the University of Minnesota’s College of Pharmacy and founding director of the Institutes for Therapeutics Discovery and Development, who said: “The last innovation in contraception was the birth control pill for women, and that’s more than 60 years ago. The world is ready for a male contraceptive agent and delivering one that’s hormone-free is simply the right thing to do given what we know about the side effects women have endured for decades from The Pill.  We consciously chose to inhibit the vitamin A signaling pathway in the testis because nearly 100 years of research has validated this pathway and shows that infertility can be reversed easily. Our preclinical data is strong, showing that YCT-529 was 99% effective in preventing mouse pregnancies and decreasing monkey sperm counts after two weeks of dosing. YCT-529 has also demonstrated a strong safety profile, and full reversibility in mice and monkeys once treatment ended. I commend the YourChoice Therapeutics team for taking this candidate into the clinic and feel confident in its safety profile, which the phase one study will affirm.”

“Contraceptives work only if they’re used,” said Akash Bakshi, co-founder and CEO of YourChoice Therapeutics. “YCT-529 blocks a protein—not hormones—to prevent sperm production. We believe this will be more attractive to men, most of whom view pregnancy prevention as a shared responsibility even despite today’s limited contraceptive options, which are permanent or only moderately effective. The dearth of options reinforces the centuries-old view that pregnancy prevention is ‘a woman’s responsibility.’  It’s not, and we’re committed to advancing the first hormone-free birth control pill for men that’s effective, convenient, and temporary. We thank our investors and the male volunteers who have stepped forward to be a part of this mission.”

The Male Contraceptive Initiative has contributed generous funding to the development of the first hormone-free male birth control pill since its inception. Executive Director Heather Vahdat commented: “While most men view pregnancy prevention as a shared responsibility, they have few options to participate. The first human study for a hormone-free male birth control pill is a long-awaited milestone and a landmark achievement in the quest for reproductive autonomy. While significant work lies ahead, we believe YCT-529’s first human study is a significant step toward a future where both men and women have the power to decide and control contraceptive use, pregnancy, and childbearing, a kind of health equity we believe is long overdue.”

“A male birth control pill has been the holy grail of contraceptive research and development for decades, and YourChoice Therapeutics is positioned to be a pioneer in this field,” said Maryanna Saenko, Co-founder and Partner at Future Ventures. “YCT-529 represents the first hormone-free therapy, finally enabling men to have an effective birth control  option without interfering with their hormones. YourChoice Therapeutics has a world-class team and strong preclinical results guiding this next phase one study, which we believe brings us one step closer to a paradigm shift in how men and women view and participate in contraception planning.”

The phase one study will investigate the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending oral doses of YCT-529 in 16 participants. Quotient Sciences, based in the UK, is conducting the phase one study. Male volunteers who would like to enroll are invited to contact Quotient Sciences at for consideration.

About YCT-529
Researchers have understood for decades that vitamin A is essential for male fertility. YCT-529 is a retinoic acid receptor-alpha (RAR-a) inhibitor that prevents production of sperm cells in the testes as well as their release by blocking RAR-alpha (one of three nuclear receptors that bind retinoic acid, a form of vitamin A). Several preclinical studies have shown YCT-529 is 99% effective at preventing mouse pregnancies and 100% reversible. YourChoice Therapeutics developed YCT-529 in collaboration with Dr. Gunda Georg, a globally recognized medicinal chemist and awardee of one of the largest NIH-funded Contraceptive Centers. The Male Contraceptive Initiative (MCI) has been committed to funding both the early research as well as YCT-529’s phase one clinical trial in men, which is underway at Quotient Sciences in the UK. More information about the trial can be found at, NCT06094283.

About YourChoice Therapeutics 
YourChoice Therapeutics is an early-stage biopharmaceutical company focused on developing the first hormone-free birth control pill for men. Based in San Francisco, the company is currently studying YCT-529 in a phase one clinical trial. In preclinical studies, YCT-529 performed as effectively or better than the female birth control pill. Future programs will apply the company’s patented therapeutic platform to develop hormone-free family planning products for women. Established in 2018, the company received a $15M Series A investment in 2022. For more information, visit and follow the company on LinkedIn.

Media: Shanti Skiffington | Mobile: 617-921-0808