The male contraceptive gel Vasalgel was shown effective in preventing pregnancies in trials conducted on a group of rhesus monkeys.
Results of the trial, which was published in Basic and Clinical Andrology on Feb. 7, showed that despite typically high pregnancy rates of about 80 percent in female monkeys housed with males, no pregnancy occurred over the study period covering at least one breeding season when the males were treated with the contraceptive gel.
Better Alternative For Traditional Vasectomy
The findings offer hope for a new birth control method that men can use. If proven effective and safe enough for humans, Vasalgel could be an alternative for vasectomy.
"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," said Catherine VandeVoort, from the California National Primate Research Center. "Chances are, it's going to be effective in humans."
Withdrawal method and condoms are currently the best option for these men but withdrawal method poses high pregnancy risk and condoms can disrupt spontaneity during sexual contact. Although vasectomy is highly effective, it is poorly reversible, which means it is not the best option for those who need temporary protection.
Based on earlier trials involving rabbits, Vasalgel could be a sort of a reversible vasectomy albeit results of animal studies still need to be replicated in humans.
Side Effects Of Other Experimental Male Contraceptives
While other studies are also being conducted to develop a male hormonal contraceptive that can be as effective as the birth control pills taken by women, scientists are concerned over the unwanted side effects of these types treatment which include depression and soaring libido.
The Vasalgel though does not interfere with the production of sperm nor changes the hormone levels in the body, which means that the side effects seen in hormone-altering pills, gels, and injections would not be an issue.
Potential Complications Associated With Use Of Vasalgel
While VandeVoort and colleagues reported that use of Vasalgel was well tolerated in monkey subjects, there are still issues and complications that arose due to use of the contraceptive gel. The researchers, for instance, inserted the gel into one of the 16 monkeys involved in the trial incorrectly.
"Complications during Vasalgel placement in one animal (Animal 3) were associated with damage to the wall of the vas deferens, likely as a result of incorrect placement of the catheter, resulting in incomplete penetration of the wall of the vas deferens," the study researchers wrote in their study.
"This resulted in extraluminal leakage of Vasalgel within the thin fibrous sheath surrounding the vas, likely weakening the overall structure."
Another subject also developed sperm granuloma. The condition, which is caused by leaking sperm, is characterized by a lump of sperm forming at the site where the vas deferens, the tube that carries the sperm from the testes to the penis, is tied off. Granuloma commonly occurs after vasectomy.
Inflammation, which also commonly occurs after vasectomy, however, was minimal with Vasalgel.