Male Birth Control Gel Inches Toward a Breakthrough

Birth control for men pretty much boils down to two things: condoms and a vasectomy. But a new product called Vasalgel could offer an alternative. A successful test in monkeys suggests that it’s not far off from becoming a big breakthrough for an area of medicine that’s been lacking for years.

From hormone-based pills and injections to diaphragms, IUDs, and vaginal rings, contraception options for women are widespread. The reason so few options are available to men comes down to two factors.

The first is biological: preventing a single egg from reaching its destination once per month is easier than blocking the daily production of millions of sperm cells. Second, there simply isn’t much funding around for developing male birth control drugs.

As we wrote back in November, the World Health Organization did sponsor a trial of a hormonal injection for men that seemed to work. But the drug had serious side effects, and the trial was stopped. A similar drug tested in 1,045 men in China proved effective and was reversible, but the company that made it, Zhejiang Xian Ju Pharmaceutical, never brought it to market. An array of pills are also in development around the world, but none have yet made it to the pharmacy.

Vasalgel, made by the nonprofit Parsemus Foundation, is a polymer gel that is injected into the vas deferens, the sperm-carrying tube that is severed and cauterized in a vasectomy. The gel blocks sperm from making their way out of the testes.

So far, Vasalgel has been tested in a range of animals. In the latest results, published in the journal Basic and Clinical Andrology, 16 male rhesus monkeys were injected with the gel and returned to live alongside females. No pregnancies were found over the course of two years of monitoring, and side effects were limited to one misplaced injection that necessitated a vasectomy.

The trick now will be to prove that the procedure is reversible. A similar technique in trials in India, called RISUG, has shown itself to be reversible, but has struggled to sign up enough volunteers. Vasalgel's trials, meanwhile suggest it is effective at preventing pregnancies, but tests in large animals have yet to show it is easier to undo than a vasectomy.

(Read more: The Guardian, “Why We Still Don’t Have Birth Control Drugs for Men”)