A gel-based substance promises to render men incapable of fertilising eggs for up to two years – which could help balance the load placed on women for preventing pregnancy
Scientists have unveiled the world’s first contraceptive implant for men, with promising results so far in its clinical trials.
Experts at a US-based biotech company called Contraline have been working on a non-hormonal water-soluble hydrogel, which is injected into a man’s sperm duct to stop sperm from getting into the urethra, thereby preventing pregnancy.
The effects last for two years before fertility goes back to normal, says the company.
The product, called ADAM, is being tested on 25 men and the first human trial is currently 18 months into its three-year run. So far, two of the patients have reached the 24-month mark, and tests revealed they still have no sperm in their semen.
There have been no serious adverse events reported so far, but further research will be taken to ensure ADAM is safe enough to be put on the market – and effective at preventing pregnancy.
Dr Alexander Pastuszak, Contraline’s chief medical officer, said: “Our goal was to create a male contraceptive option lasting two years, responding directly to consumer needs.
“These findings confirm that ADAM, our novel water-soluble hydrogel, can achieve the intended lifespan. We remain optimistic about its safety, efficacy, and reversibility, and its potential to give men and couples greater reproductive control.”
To date, men have only had one barrier method of contraception – condoms – or can opt for a vasectomy, which severs the vas deferens – tiny tubes that carry sperm from the testicles to the urethra. This stops sperm from mixing with semen and being released at the point of ejaculation, which allows men to orgasm without risking pregnancy in their partner.
The ADAM implant works in a similar way but is reversible because it doesn’t involve surgery. Instead of sealing the tubes, ADAM is injected into the sperm duct (located just underneath the scrotum) and blocks sperm from travelling through the vas deferens.
This means patients can still ejaculate, but there will be no sperm swimming inside his semen.
Contraline’s researchers say the gel implant is “minimally invasive” and can be injected in under 10 minutes, with the use of a local anaesthetic to prevent pain. After its lifespan, the gel breaks down into a liquid and is carried out of the body with its normal waste to allow a return to normal fertility.
It comes as a male pill is also under development following some promising results in trials on mice.
The hormone-free contraceptive tablet, called YCT-529 by its US developers, works by blocking access to vitamin A in the testes, which halts sperm production.
Like ADAM, it promises to be fully reversible after patients stop taking it. Trials so far have found it blocks 99 percent of pregnancies on mice, which is the same as the female pill.
“A safe and effective male pill will provide more options to couples for birth control,” said Gunda Georg, chemist and pharmacist at the University of Minnesota.
“It will allow a more equitable sharing of responsibility for family planning and provide reproductive autonomy for men.”