A contraceptive gel given as an injection has been found to provide long-term and reliable contraception in male monkeys, raising hopes of a new form of birth control for men who want to ditch the condom and also do not want to go for vasectomy.

The gel was able to prevent any conceptions occurring in a test group of 16 rhesus monkeys, show the results published in the journal Basic and Clinical Andrology.

The researchers believe that this method has the potential to offer men a reversible alternative to vasectomy, a surgical procedure for male sterilisation.

"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," explained lead author Catherine VandeVoort from the California National Primate Research Centre in the US.

Vasalgel is a non-pharmaceutical agent that forms a non-toxic hydrogel when injected into the vas deferens (the duct which conveys sperm from the testicles to the urethra). 

The gel fills the internal cavity of the vas deferens, forming a mechanical barrier to the movement of sperm. 

"Our research shows that Vasalgel placement into the vas deferens produces reliable contraception in mature male rhesus monkeys as shown by the lack of pregnancies in reproductively viable females with which the males were housed," VandeVoort said.

"Importantly, we show that the method of Vasalgel placement is safe and produced fewer complications than usually occur with a vasectomy," VandeVoort added.

The product was tested on rabbits in 2016.

"Vasalgel shows real promise as an alternative to vasectomy because research in rabbits has previously shown the product to be reversible," VandeVoort noted.