It's an "injectable vasectomy" - one quick shot and you're infertile. As soon as you’re ready to have babies, another shot reverses the effect.
The proper name is Reversible Inhibition of Sperm under Guidance, shortened to the less-than-catchy RISUG. It’s the brainchild of scientist Sujoy Guha of the Indian Institute of Technology Kharagpur.
Fifteen minutes is all it takes for a doctor to inject the gel into the vas deferens, the tube that sperm swim through on their way from the testes to the penis. After three days the contraceptive is ready to work.
The procedure is actually pretty similar to a normal vasectomy. That means it's not really just an injection but a minor operation in a very tender spot. But instead of being snipped or tied, the sperm tube gets a shot of gel.
The gel lines the walls of the vas deferens and acts like a booby trap for sperm. As soon as they set off along the tube they die - they're actually zapped by an electrical charge.
Then years, months or even days later, if a man decides he’s ready to have children, the vasectomy can be reversed. A second injection flushes out the gel and in no time sperm are swimming again.
RISUG dodges a side-effect of vasectomy, because the zapped sperm still flow out of the body with all the rest of the seminal fluid. With a conventional vasectomy, the sperm end up trapped inside the body, and can cause painful little lumps called granulomas.
Men who are pretty sure they don’t want more kids could benefit from a reversible vasectomy. But it could also be a good option for guys who aren’t ready for kids yet, or couples who want to space out pregnancies.
Long-term birth control for men could also be great news for women, sparing them the side-effects of the pill or other hormonal birth control methods. And they wouldn’t need to worry about whether a guy has remembered to take a ‘male pill’.
RISUG seems to be a very reliable form of birth control. But the research process has faced some setbacks. Back in 2002, the World Health Organisation said Sujoy Guha’s trials weren’t up to scratch, and the Indian Council of Medical Research said more tests were needed to be certain the injection isn't toxic.
What’s more, although the whole idea of RISUG is that it’s supposed to be reversible, the process of flushing it out again hasn’t actually been tested on humans yet.
Research into contraception for men began in the 1970’s, mostly with hormonal methods. Today, different non-hormonal male birth control methods are being tested, like the ‘dry orgasm pill’. Men taking the pill don’t ejaculate any semen when they come.
There are also painless heat and ultrasound treatments for the testicles. And even plants from parts of Asia that have short-term birth control effects.
But the reversible vasectomy might just be the most promising option of them all. RISUG has now been tested by some men in India for as long as 20 years, and the final phase of trials is underway.
In the USA, where it’s called Vasalgel, men will probably be able to take part in trials this year.
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