Male Contraceptive Gel Works With Monkeys, Human Trials In The Works

Male Contraceptive Gel Works With Monkeys, Human Trials In The Works

A new form of male contraceptive has proven to be effective when tested on rhesus monkeys. And if all goes according to plan, researchers may one day conduct their first human trials, as they work on developing what could potentially be a more sustained form of birth control for men.

The gel-like substance in question is known as Vasalgel, and according to BBC News, it creates a “physical barrier” once it is administered via injection into the vas deferens — the ducts responsible for transporting sperm into the penis. A separate report from the Huffington Post noted that it is one of a few male contraceptives currently being tested by researchers, and one whose test results were published a few months after a hormonal form of male birth control proved effective.

That form of hormonal birth control had worked in 96 percent of test subjects who completed the study, the Huffington Post added. However, the team behind it had run into some snags along the way, and it may need to be reformulated or retested due to a number of “mostly mild,” yet still negative side effects reported by the participants.

There are only two widely-used forms of contraceptive for men. Condoms are easily available to consumers but aren’t always effective in catching the sperm. Vasectomies work by sealing the tubes that deliver sperm from the testicles to the penis, but are, in most cases, permanent and very difficult to reverse if a man changes his mind and wants to have children. Vasalgel offers a similar effect, but researchers are optimistic that a second injection of the gel would reverse the process and remove the gel plug that was previously created.

Over a span of two years, scientists studied 16 adult rhesus monkeys and injected Vasalgel into ducts in the male monkeys’ testes to see how they would react to the new contraceptive. The tests showed that the gel had blocked the animals’ sperm, and that the female monkeys were not able to conceive. That was despite the fact that the monkeys whose testes were injected with Vasalgel had engaged in “normal breeding behavior” with their mates.

According to study lead author Catherine VandeVoort of the California National Primate Research Center, the main takeaway of the study was the safety of Vasalgel as a male contraceptive administered via injection, and how the gel didn’t cause too many setbacks in the test subjects.

“Importantly, we show that the method of Vasalgel placement is safe and produced fewer complications than usually occur with a vasectomy.”

While the positive test outcomes on the rhesus monkeys was good news for the researchers, more research may be needed, particularly to see whether the process can indeed be reversed. This was a point brought up to BBC News by University of Sheffield professor of andrology Allan Pacey, who was not involved in the Vasalgel study.

“In order for (the male contraceptive gel) to have a chance of replacing the traditional surgical method of vasectomy, the authors need to show that the procedure is reversible.”

The Huffington Post wrote that there were some other issues in the tests, as three of the rhesus monkeys experienced some adverse side effects. The first was a case of the Vasalgel being incorrectly injected into the left vas deferens, thus forcing a vasectomy on the left side and a second gel injection in the right vas deferens. A second monkey was found to have a lump with leaking sperm in it – a common vasectomy side effect in humans. The third monkey who experienced complications was partially castrated after getting physically aggressive with the other monkeys. The researchers believe this was not related to Vasalgel, but rather to “normal breeding season conflicts.”

Considering those challenges and others, it may take some time before Vasalgel makes it to the mainstream and becomes a commercially-available birth control option. The researchers hope to gather more evidence of Vasalgel’s efficacy and get more funding to begin tests on human males “within a few years,” BBC News added. Provided those tests go well, the scientists will then seek regulatory approval, in hopes of having the male contraceptive gel marketed to consumers.

[Featured Image by Brennan Linsley/AP Images]