A novel male contraceptive technique that has long-lasting effects and reversibility like an IUD (intrauterine device) used in women has shown positive results in a human clinical trial.

The new product, named ADAM and developed by Contraline, has a hydrogel insert, which when injected into the sperm duct could reduce sperm motility and concentration similar to that of a vasectomy. However, unlike vasectomy, the contraception is fully reversible.

Vasectomy is an effective birth control option for men in which the tubes that carry sperm to the testicles are surgically cut off and sealed. The procedure is pretty much permanent. Vasectomy reversal is expensive and may not necessarily work.

"Right now, there is nothing out there that's long-lasting and reversible for men. This is made for people who are not ready to have kids, are spacing out having kids, or think they are done having kids but maybe not ready for that permanent option," said Kevin Eisenfrats, co-founder and CEO of Contraline.

The trial involved 23 healthy men between 25 and 65 years from across three places in Australia —Melbourne, Brisbane and Wollongong — who were suitable for vasectomy. In a 20-minute procedure, the soft, water-based hydrogel was inserted into the participants under local or general anesthesia. The researchers noticed a 100% successful implantation rate.

The participants showed a 99.6-100.0% reduction in motile sperm count within 30 days of implantation, the efficacy matching with that of vasectomy. There were no significant adverse events reported.

"I am pleased with the early results we are seeing from the trial; it is exciting to see the preliminary outcomes showing ADAM is safe and effective. The level of participant interest we are seeing shows that there is a major need for this type of contraception, and I am excited to continue working with Contraline in the development of the device," said Dr. Peter Chin, a study investigator from the University of Wollongong.

"We are thrilled to share these positive results which we believe take us one step closer to transforming the contraceptive landscape. This trial and the data presented are a clear indication that ADAM is safe, effective, easy to use, and in demand. The fact that we are seeing such a dramatic reduction in sperm counts and motility, without compromising on safety, suggests that it is possible to achieve similar levels of efficacy as long-acting female contraceptives like IUDs. Ultimately, I'd like to make ADAM become a 'no brainer' for men when it comes to considering their options for contraception," Eisenfrats said.

The gel is designed to dissolve itself at the end of its lifespan, which is expected to be one or two years. The participants will be followed up for two years to know the exact duration.

Men who wish to restore fertility before the end of the gel's lifespan can do so by removing the gel, researchers said. They have tested the reversibility in dogs and plan to launch a second trial to test the on-demand reversibility in people.