A male contraceptive gel has performed reliably in primate trials, showing that the long-sought after goal of male birth control may not be too far off. The new product could become a less invasive and more easily reversible substitute for vasectomies. The gel, called Vasagel, is injected into the vas deferens – the tubes that contain sperm in the male reproductive system. The gel acts as a long-term barrier to sperm.
Earlier trials in other animals showed that the procedure was easily reversible. The gel was able to be easily flushed out with a sodium bicarbonate solution.
The lead author of the study, Catherine VandeVoort, from the California National Primate Research Center, said:
“Men’s options for contraception have not changed much in decades. There’s vasectomy, which is poorly reversible, and condoms. If they knew they could get a reliable contraceptive that could also be reversed I think it would be appealing to them.”
“One of the great things about the monkey model is that the male reproductive tract is very similar to humans and they have even more sperm than humans do. Chances are, it’s going to be effective in humans.”
According to the Parsemus foundation, the non-profit who funded the research, human trials are planned to start as soon as they secure funding in the wake of the success results with monkeys.
Progress toward male contraceptives has largely stagnated for decades. Recently, however, a number of different attempts to create one have shown promise. The World Health Organizatiion published results last year that showed a male hormonal contraceptive jab to be as effective as a female contraceptive pill. That method, however, included problematic side effects such as depression and acne linked to hormonal contraceptives, that scientists are still working to overcome.
The Vasagel procedure, however, does not alter sperm production or hormone levels, avoiding such unwanted side effects. Similar to a vasectomy, the Vasagel allows sperm to dissolve to be absorbed by the body instead of being ejaculated.
However, the Vasagel procedure is reversible, unlike the cutting and cauterizing involved in a vasectomy procedure.
“They wouldn’t have to worry about it on a day-to-day basis. This would be more akin to an IUD [the coil] in women,” according to VandeVoort.
In the new research, 16 male rhesus monkeys were given the Vasagel procedure before being returned to their group, which included breeding females. The monkeys were monitored for one breeding season, and about half the monkeys lived with females for two years. There were no conceptions, and minimal side effects, including some inflammation. The research was published in the journal Basic and Clinical Andrology.