Vasectomy Alternative: Male Contraceptive Gel Proves Effective in Animal Models

From birth control pills and injections, to intrauterine devices (IUDs), women have the benefit of being able to choose from a wide range of contraceptives. While some pharmaceutical companies have tried in the past to develop a male contraceptive, so far none has been successful at making a safe and effective male birth control.

As the Centers for Disease Control and Prevention (CDC) estimates that nearly half of all pregnancies are unplanned, there is a clear need for additional forms of contraception. Now, a company known as Revolution Contraceptives have developed a male non-hormonal contraceptive gel, named Vasalgel.

Last year, researchers tested Vasalgel in rabbits, and found that the product could rival vasectomies in terms of its successfulness as a long-term male contraceptive. A recent study – published in the journal, Basic and Clinical Andrology – tested the drug in monkeys and found similarly promising results.

Vasalgel is a high molecular weight polymer, which could offer a reversible contraceptive option for men. The drug is injected into the tube which carries sperm from the testicles to the urethra – known as the vas deferens – where it forms a resistant barrier to prevent the ejaculation of sperm.

To test the safety and effectiveness of Vasalgel, the drug was injected into 16 adult male rhesus monkeys, and the results were compared to the same number of monkeys who were previously vasectomized. After recovering from the procedure, the animals were returned to group housing facilities where they cohabitated with females for a breeding period of six months to two years.

Offspring resulting from this cohabitation were tested for paternity based on genetic testing of blood samples. None of the males treated with Vasalgel injections had any offspring.

The researchers reported that the Vasalgel injection was found to be relatively safe, resulting in only a few complications. For example, one monkey developed a buildup of sperm in the vas deferens – known as a sperm granuloma – which is also a common complication of vasectomies.

“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,” said Dr. Catherine VandeVoort, senior author of the study and researcher at the California National Primate Research Centre. “Importantly, we show that the method of Vasalgel placement is safe and produced fewer complications than usually occur with a vasectomy.”