A new male birth control implant has shown promising results in early trials, offering a long-lasting and reversible way to prevent pregnancy. The implant, called Adam, uses a hydrogel to block sperm and has remained effective for over two years in the first human tests.
New Hope for Male Contraception
Developed by biotechnology company Contraline, Adam is a soft, water-based gel. It is placed directly into the vas deferens, the tubes that carry sperm from the testicles. The simple outpatient procedure takes about 10 minutes and only requires local anesthesia.
Unlike condoms or vasectomies, Adam provides a non-hormonal, long-term, and reversible solution. The hydrogel works by forming a barrier that prevents sperm from mixing with semen during ejaculation. Over time, the gel naturally breaks down and is absorbed by the body, allowing fertility to return.
Promising Clinical Trial Results
Contraline recently shared data from its Phase 1 clinical trial, which included a small group of men. So far, two participants have reached the 24-month mark, and in both cases, no sperm was detected in their semen. The company confirmed that no serious side effects have occurred during the study.
“This is the first clear evidence that a two-year, reversible male contraceptive is possible,” said Kevin Eisenfrats, CEO and founder of Contraline. He emphasized that the procedure is safe, quick, and simple—comparable to getting a dental filling.
Designed to Break Down Naturally
What makes Adam stand out is its biodegradable hydrogel. Earlier experimental male contraceptives used materials that stayed in the body, which sometimes caused scarring or permanent infertility. In contrast, Adam is designed to dissolve naturally, with no long-term harm to the reproductive system.
Although human reversibility data is still pending, animal trials have shown that the hydrogel dissolves consistently, allowing sperm to flow normally again. Smaller earlier studies in men also suggested that the contraceptive effect fades over time.
Eisenfrats compared the product to an IUD for men. “After two years, men can choose to get another implant or not. In the future, we plan to offer a method for on-demand reversal,” he said.
Larger Trials and Home Testing
Contraline plans to begin a Phase 2 clinical trial in Australia later this year. It will involve 30 to 50 participants and focus on confirming effectiveness, safety, and reversibility over a longer period.
Researchers are also working on at-home sperm testing kits that could allow men to monitor the implant’s effect. This would give users more confidence and control over their fertility.
Experts Urge Caution Until Reversibility Confirmed
Health experts say Adam’s trial results are encouraging but warn that more research is needed. Professor Richard Anderson of the University of Edinburgh said, “This is an exciting step forward for male contraception, especially in the non-hormonal space.”
However, he and Professor Jon Oatley of Washington State University both stressed that reversibility is not yet proven in humans. Oatley noted that blocking the vas deferens could have unknown long-term effects and that some men might prefer options like pills or patches that don’t require surgery.
“Until we know more about how fertility is restored, we should proceed carefully,” Oatley said.
A Turning Point in Male Reproductive Health?
If further trials confirm its safety and reversibility, Adam could be a game changer. Current male contraceptive options are limited, with condoms being the most widely used and vasectomies often considered permanent. Adam offers a middle ground: a method that is long-lasting but not permanent, and non-hormonal with minimal side effects.
With growing interest in shared contraceptive responsibility, Adam could help balance the burden that has long fallen on women. Its success may also inspire greater investment in male reproductive health research, a field that has historically been underfunded.