A new type of hydrogel that stops the flow of sperm has successfully prevented pregnancy in female monkeys, according to a new study funded primarily by the Parsemus Foundation and published in Basic and Clinical Andrology.
There are currently three main forms of male contraceptives: condoms, withdrawal, and vasectomies. The new option, known as Vasalgel, is injected directly into the vas deferens — the tube that carries sperm from the testicle to the urethra — where it blocks sperm flow by turning into an adhesive and blocking the passage.
To test the substance, researchers from the University of California, Davis administered it to 16 male rhesus macaques, 10 of which had already impregnated females. After the team injected the goo, the primates were given a week to recover before being housed with females over the course of an entire breeding season. Despite the close quarters, no pregnancies occurred.
“[W]e were impressed that this [procedure] worked in every single monkey, even though this was our first time trying it,” said lead author Dr. Angela Colagross-Schouten, a veterinarian at the University of California, Davis, in a statement. “Vasectomies are a routine procedure for nonhuman primate veterinarians, so to have similar or even slightly better outcomes trying a brand-new procedure is very encouraging.”
While this data suggests the procedure is effective at preventing pregnancies, it did come with some minor complications. However, those issues were less frequent than the problems that occurred with monkeys that underwent vasectomies, Live Science reports.
“Intravas injection of Vasalgel in sexually mature adult male rhesus monkeys was effective in preventing conception in a free-living, group environment,” the researchers wrote in their study, according to Tech Times. “Complications were few and similar to those associated with traditional vasectomy.”
Though the new substance is promising, there are still many more questions that need to be answered. For instance, while past studies have shown it is possible to reverse the process in rabbits by flushing out the Vasalgel, that has not yet been tested in monkeys. In addition, researchers are not sure if the procedure will be safe or effective for humans. Those trials are likely the next step.