YourChoice Therapeutics Advances Male Contraception with Second Nature Portfolio Publication Showcasing Human Trial Data for YCT-529
YourChoice Therapeutics, Inc., a clinical-stage biopharmaceutical company pioneering the development of hormone-free contraceptive solutions, has announced a significant milestone with the publication of its second study in a Nature Portfolio journal. The new study, published in Communications Medicine, details the results of the first-in-human clinical trial of YCT-529, the company’s investigational non-hormonal oral contraceptive for men.
This publication marks an important step forward in the field of male contraception, offering fresh evidence supporting the safety and tolerability of YCT-529. The peer-reviewed manuscript, titled “Safety and Pharmacokinetics of the Non-Hormonal Male Contraceptive YCT-529”, reports that single doses of the drug—administered in escalating amounts up to 180 mg—were well tolerated by participants and had no measurable impact on hormonal balance, sexual desire, or mood. Notably, this follows a previous publication in March 2025 describing compelling preclinical data, making this the second publication involving YCT-529 in a Nature Portfolio journal within just a few months.
A New Era for Male Contraception
YCT-529 is designed to fill a critical gap in reproductive healthcare. As a first-in-class, non-hormonal, orally administered male contraceptive, it is being developed to address longstanding challenges associated with male birth control. Historically, options for men have been limited to condoms or surgical vasectomy—methods that are either prone to failure or irreversible. Hormonal contraceptives for men, while investigated in the past, have largely stalled in development due to undesirable side effects, poor efficacy, or lack of compliance.
By contrast, YCT-529 works via a novel biological mechanism. It is a retinoic acid receptor-alpha (RAR-α) antagonist, which disrupts a vitamin A pathway that is critical to the development of sperm. The specificity of YCT-529 for the RAR-α receptor has been demonstrated in preclinical models, where the compound showed 99% efficacy in preventing pregnancy in mice, complete reversibility within six weeks, and no apparent side effects. These studies also extended to non-human primates, providing further evidence of translatability to human biology.
The human trial results now add another crucial layer of validation to this compound’s safety and tolerability profile.
Details from the First-in-Human Study
The recently published Phase 1a study, conducted by UK-based Quotient Sciences, enrolled 16 healthy male participants between December 2023 and June 2024. Participants were given single ascending doses of YCT-529, ranging from low to high concentrations, with the maximum dose tested reaching 180 mg.
According to the publication, no serious adverse events or safety concerns were reported throughout the study. The drug had no measurable effect on testosterone levels, heart rate, complete blood counts, or liver and YourChoice kidney function. Additionally, sexual function, libido, and mood remained stable, an essential consideration given the psychological and emotional concerns historically linked to hormone-based male contraceptive candidates.
“The peer-reviewed publication of our first-in-human study further affirms the favorable safety profile of YCT-529,” said Dr. Nadja Mannowetz, Chief Science Officer at YourChoice Therapeutics and the study’s lead author. “These results are a strong foundation as we move into the next phase of clinical development. It’s particularly important that the drug showed no effect on sexual desire or mood, which has been a major hurdle for past efforts in male contraception.”
Expanding Clinical Research: Phase 1b Underway
Building on the YourChoice success of the Phase 1a trial, YourChoice has initiated a multiple ascending dose (MAD) study, which is currently being conducted by New Zealand Clinical Research (NZCR). This new trial aims to enroll up to 50 healthy male volunteers and will assess not only safety and tolerability but also YCT-529’s impact on sperm count—the ultimate marker of contraceptive efficacy.
While the MAD study is still ongoing, YourChoice believes these back-to-back clinical milestones significantly bolster YCT-529’s candidacy as the first non-hormonal male birth control pill to reach advanced stages of human testing. The company is optimistic that, pending successful outcomes from this and future studies, YCT-529 could enter pivotal trials in the near future.
Societal Implications and Demand
The need for innovation in male YourChoice contraception is both urgent and globally relevant. According to estimates from the Guttmacher Institute and the World Health Organization, nearly 50% of pregnancies worldwide are unintended. Much of the burden of contraceptive use falls on women, despite growing evidence that men are not only open to but actively interested in sharing this responsibility.
A recent international survey cited by YourChoice indicates that a significant percentage of men—particularly in younger demographics—are willing to use new male contraceptive options, especially if they are oral, non-invasive, and free from hormonal side effects. Similarly, many women report high confidence that their partners would use such a product responsibly, which reflects a cultural shift toward shared reproductive accountability.
“There is a profound mismatch between the desire for male contraceptive options and what’s currently available,” said Akash Bakshi, CEO and Co-founder of YourChoice Therapeutics. “Right now, men have just one non-permanent option—the condom—and it’s a method that dates back over 170 years. Scientific and social progress has far outpaced our contraceptive toolkit. YCT-529 could be the disruptive innovation this space has needed for generations.”
Bakshi added that the market potential for a reliable, hormone-free male pill is enormous, especially given increasing calls for gender parity in reproductive health.
Scientific Backing and Historical Basis
YCT-529’s mechanism of action is backed by nearly a century of biological research. The vitamin A metabolic pathway, specifically its role in male fertility, has been studied extensively since the 1920s. Retinoic acid—a metabolite of vitamin A—is essential for spermatogenesis, the process by which sperm are developed in the testes. By selectively targeting the RAR-α receptor, YCT-529 inhibits this pathway without affecting other hormonal systems, making it a uniquely targeted approach.
This precise selectivity is one of YCT-529’s key advantages over hormonal agents, which can affect testosterone, estrogens, and other hormone-dependent systems, leading to side effects such as mood swings, reduced libido, fatigue, and even depression.
As YCT-529 progresses through clinical development, YourChoice Therapeutics remains focused on executing rigorous, science-driven studies to bring this first-in-class therapy to market. With mounting clinical evidence, increasing public interest, and growing support from the reproductive health community, the company sees YCT-529 not just as a product, but as the foundation of a broader movement to transform male reproductive healthcare.
“We’re doing more than just developing a drug,” said Mannowetz. “We’re catalyzing a shift in how society thinks about male involvement in family planning. And we’re doing it with data, integrity, and urgency.”
As the field of male contraception enters a long-overdue phase of innovation, YourChoice’s second Nature Portfolio publication marks a defining moment in the effort to provide equitable and effective contraceptive options for all.
