A Gel Injected Into the Scrotum Could Be the Next Male Contraceptive

Men in the trial ranged from age 25 to 65 and were placed into two groups that received different amounts of hydrogel: a lower volume and a higher one. Implanting the gel took about 20 minutes and was done under local anesthesia, unless someone chose to be sedated instead.

Eisenfrats says sperm concentration and movement in the men are comparable to levels seen with a vasectomy. “We’re seeing that this is working.”

The purpose of the current trial is to assess the gel’s safety and longevity, not how well it prevents pregnancy. Participants were asked to use a back-up form of birth control while being enrolled in the trial.

The gel is designed to dissolve at the end of its lifetime, so the men will be followed for two years to determine how long it takes for that to happen. Eisenfrats says the goal is to have a product that lasts one to two years.

But men might want to restore their fertility before that time frame, so Contraline wants to show that it can safely reverse the procedure. The company has tested the reversibility of the gel in dogs, showing that sperm counts and sperm quality rebounded after removing the gel. It plans to launch a second trial this year to test the on-demand reversibility in people. Only men who said they do not want to have children were included in the initial trial.