Male Contraceptive Effective In Rabbits [STUDY]

Scientists may have taken a major step forward in developing an effective male contraceptive gel.

For years researchers have been working on ways to remove sperm from male semen. If an effective way of doing so can be developed, it would spark a major change in how we consider reproductive health.

Male Contraceptive Effective In Rabbits [STUDY]

A new contraceptive option could be on its way

As it stands there are several options available for preventing pregnancy. The most widely used is condoms, which also prevent the spread of most sexually-transmitted infections. Some women choose to take contraceptive pills, but side effects are common and often unwelcome due to the hormones that the pills contain.

Another solution is a contraceptive implants such as the Bayer Essure. However these too present unwelcome side effects, and Bayer has been ordered to carry out further clinical trials of Essure by the FDA. Some women have reported abdominal pain after having the device installed.

Until now the only male contraceptive option has been a vasectomy. As a result of this latest research we may be moving closer to a male contraceptive that is only semi-permanent. Scientists have found that an injectible gel effectively eliminated the presence of sperm in rabbits’ semen in a new study.

Study shows male contraceptive gel effective in rabbits

Vasalgel, as the substance is known, was found to completely stop the flow of sperm after it was injected into the rabbits. The flow returned to normal after the gel was removed, say the researchers.

The gel could be the first male contraceptive that is not permanent. Men can opt to undergo a vasectomy, but it is considered to be a permanent solution, say researchers. It could lead to a revolution in reproductive health.

Vasalgel is made from a styrene-alt-maleic acid dissolved in dimethyl sulfoxide. It is injected into the vas deferens, where it turns into a hydrogel which lets water-soluble molecules through, but not sperm.

The gel is soft, meaning that it can flex and remain in position, thereby preventing sperm from passing.

Human clinical trials planned for later this year

“Results from our study in rabbits were even better than expected,” said Dr. Donald Waller, a professor of pharmacology and toxicology at the University of Illinois. “Vasalgel produces a very rapid contraceptive effect which lasted throughout the study due to its unique hydrogel properties. These features are important considerations for a contraceptive product to be used in humans.”

The paper was published in the journal Basic and Clinical Andrology. The study used 12 rabbits treated with two different formulations of Vasalgel. 11 of 12 rabbits did not show any sperm after receiving an injection, while the one remaining rabbit displayed a small amount of sperm at first before becoming azoospermic.

Scientists are planning to carry out a human clinical trial in late 2016.

“We expect [that time frame] to be similar in men, but that is just a minimum,” said Elaine Lissner, executive director of Parsemus Foundation, the organization that developed the drug. “It seems to be pretty durable; we expect it to last for years. We just don’t know how many yet.”

If it is approved Vasalgel would be the first long-lasting, non-hormonal, potentially reversible contraceptive for men on the market.

“Contraceptive development is a hugely expensive project. But this is not just another early-stage lead; we’re so close on this one. It’s time to finish the job we’ve started,” said Lissner.