A male contraceptive gel has been found to work in a trial in primates, offering the prospect of an alternative form of birth control for humans. The product, called Valsalgel, is designed as a type of "reversible" vasectomy
The gel is injected into the tube that carries sperm out of the testicles, the vas deferens, where it forms an impenetrable gel barrier.
The research showed that the gel could be removed by flushing the duct with baking soda solution.
In the trial, it had a 100 per cent success rate.
Dr Catherine VandeVoort, from California National Primate Research Centre, and lead scientist on the trial, said the research “showed that the method of Vasalgel placement is safe and produced fewer complications than usually occur with a vasectomy.”
She added: “Vasalgel shows real promise as an alternative to vasectomy because research in rabbits has previously shown the product to be reversible. Although it is possible to reverse a vasectomy, it is a technically challenging procedure and patients often have very low rates of fertility following reversal.”
After decades of minimal progress on male contraceptives, a range of different approaches now appear to be showing promise. A World Health Organisation investigation, published last year, found that a male hormonal contraceptive jab was as effective as the female pill.
However, scientists are still working to overcome unwanted side-effects including depression, acne and soaring libido that are linked to hormone-altering gels, pills and injections.
One of the 16 monkeys in the trial showed signs of sperm granuloma, a hard build-up of sperm in the vas deferens. The same non-serious complication affects around 60 per cent of men undergoing a vasectomy, said the researchers.
“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 Dr VandeVoort. “Chances are, it’s going to be effective in humans.”
The findings, reported in the journal Basic and Clinical Andrology, pave the way for clinical trials expected to begin next year.
The gel, which is not classified as a pharmaceutical product, is made by the non-profit Parsemus Foundation in Berkeley, California. It plans to start human trials as soon as it can secure funding. – (PA, Guardian Service)