A new study finds that a new type of male birth control pill can effectively block the flow of sperm in female monkeys, researchers said in a statement:
The success of the contraceptive pill in male monkeys means human men may be next in line for clinical trials. Currently, male contraceptive options include condoms, extubation and vasectomy, the latter of which is generally considered a permanent procedure.
However, the new birth control pill has only been tested on animals, and more research is needed to determine if it is safe for use in people and that it works.
The new birth control pill, called Vasalgel, is injected into the vas deferens (the tube that carries sperm from the testicles to the urethra), where it forms a viscous hydrogel. This hydrogel acts as a barrier, preventing the flow of sperm from the vas deferens. In a separate study in rabbits, scientists were also able to reverse the process, flushing out the vas deferens and restoring it, according to the study published today (February 6) in the journal Basic and Clinical Andrology* ** flow. In the new study, researchers performed this procedure on 16 male rhesus monkeys, including one in 10 that had impregnated a female. According to the study, the monkeys were given a week to recover from the surgery and then were housed with female monkeys for at least one breeding season. The monkeys were routinely monitored and did not become pregnant, the researchers wrote. [Animalism: 7 Stories of Naughty Behavior in the Wild]
"Although this was our first time trying it, the program worked on every monkey, which gave We were impressed," said lead study author Dr. Angela Colgros-Shorten, a veterinarian at the University of California, Davis. The researchers said in a statement:
Although this One finding suggested that the procedure could prevent pregnancy, but the researchers noted that some male monkeys experienced minor complications after the procedure, including one case of a blood vessel being injected into the wrong place.
Compared to monkeys, however, monkeys who underwent vasectomy had much lower complication rates, the researchers wrote. The researchers selected 16 monkeys of similar age who had previously undergone vasectomy and observed complications in seven of the monkeys after the surgery and in three monkeys after receiving vas deferens injections.
"Vasectomy is a routine surgery in non-human primate veterinarians, so it is very encouraging to try a completely new approach to achieve similar or even slightly better results," says Colagross Schouten.
Further research is needed to investigate the possibility of reversing the effects of injections in monkeys by rinsing the hydrogel, the researchers noted.
Previous male contraceptive pills have been studied in humans. One study used hormone injections to reduce the production of sperm, but it had to be stopped early due to unwanted side effects, such as mood disorders, in the men in the study.
This research was primarily funded by the Parsemus Foundation, which owns Revolution Contraceptives LLC, the company that holds the patent for Vaselgel.
Originally published on Live Science.