Vasalgel allows seminal fluid to be released during ejaculation but blocks sperm, which are reabsorbed by the body
Vasalgel allows seminal fluid to be released during ejaculation but blocks sperm, which are reabsorbed by the body

Contraceptive gel that creates ‘reversible vasectomy’ shown to be effective in monkeys

The gel is injected into the vas deferens, the duct between the testicles and the urethra

Katie Forster
Tuesday 07 February 2017 11:17
Comments

An injectable contraceptive gel that acts as a ‘reversible vasectomy’ is a step closer to being offered to men following successful trials on monkeys.

Vasalgel is injected into the vas deferens, the small duct between the testicles and the urethra. It has so far been found to prevent 100 per cent of conceptions.

The gel fills the interior of the passage, allowing seminal fluid to be released during ejaculation but blocking sperm, which are reabsorbed by the body.

Researchers said the latest test, on a group of 16 rhesus monkeys, showed the product was “safe and produced fewer complications than usually occur with a vasectomy”.

The gel, previously tested in rabbits, can be removed by flushing the duct with a baking soda solution.

“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,” said lead scientist Catherine VandeVoort, from California National Primate Research Centre.

“Vasalgel shows real promise as an alternative to vasectomy because research in rabbits has previously shown the product to be reversible.”

A traditional vasectomy involves cutting and sealing off the vas deferens. Complications can include infection, bruising and lumps of leaked sperm forming in the surrounding tissue.

One of the treated monkeys showed signs of sperm granuloma, this hard build-up of sperm in the vas deferens, which affects around 60 per cent of men undergoing a vasectomy and is non-serious.

Clinical trials of Vasalgel, developed by non-profit Parsemus Foundation in Berkeley, California, are expected to begin next year.

The first trials will be limited to men who accept that they may become sterile, because researchers cannot guarantee that the procedure is reversible until a separate study has taken place.

Darren Griffen, professor of genetics at the University of Kent, said an effective reversible male contraceptive treatment had the “potential to revolutionise this field of medicine”, but questioned whether the necessity of injection might limit its take-up among humans.

Adam Balen, chair of the British Fertility Society, said: “this novel approach has the potential for great promise as a male contraceptive.”

Professor Balen emphasised the importance of proving the techique’s ongoing reversibility, as did Allan Pacey, Professor of Andrology at the University of Sheffield.

“In order for it to have a chance of replacing the traditional surgical method of vasectomy, the authors need to show that the procedure is reversible and it’s reassuring that apparently such studies are ongoing,” said Professor Pacey.

“It’s interesting that there has been very little commercial interest from pharmaceutical companies in this kind of a approach and so the idea of a social venture company to develop the idea is intriguing,” he said.

“I would imagine there is a worldwide market for a new male contraceptive, but trials in humans and more long-term safety data are required before we will know if it is a success.”

A similar experimental contraceptive injection, called Risug, has been developed and tested in India.

It works by impairing sperm cells as they swim from the testicles to the urethra, unlike Vasalgel, which blocks the sperm from passing through the tube.

Around 11,000 men had a vasectomy in England in 2014-15, according to NHS Digital – a drop from around 30,000 ten years previously. Experts have suggested this could be because couples are having children later.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Please enter a valid email
Please enter a valid email
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Please enter your first name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
Please enter your last name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
You must be over 18 years old to register
You must be over 18 years old to register
Opt-out-policy
You can opt-out at any time by signing in to your account to manage your preferences. Each email has a link to unsubscribe.

By clicking ‘Create my account’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in