The 'IUD' for MEN, which is 99% effective at blocking sperm, could be available next year

A form of male contraception that prevents sperm from leaving the body using a gel has shown promise in early clinical trials.

Researchers in Virginia who injected 23 men with the non-hormonal birth control — called ADAM — said sperm counts in participants' ejaculations dropped by 99 to 100 percent just a month after the procedure.

The participants had the gel injected into the vas deferens, the tube that transports sperm from the testes to outside the body.

All men still had ejaculations, because the fluid for this is produced in a different area, but the ejaculate was devoid of sperm after the gel injection.

Kevin Eisenfrats, leader of the biotech company behind the contraception, called the results “phenomenal” and “very effective.” The results did not show it was reversible, although he said they would test this in further studies.

Some experts have raised concerns about the gel's reversibility and have warned that sperm could find a way to bypass the blockage.

Eisenfrats has previously described the gel as an 'IUD for men', as he aims for the contraceptive to be long-lasting yet reversible. But unlike an IUD, the gel does not depend on changing the hormones in the body.

Women have always been the sex responsible for contraception to prevent unwanted pregnancies, while men could only use condoms or a vasectomy – where testicular tubes are cut to prevent sperm from leaving the body.

But amid rising demand for alternatives, scientists have begun working on new technologies.

The hydrogel being developed by biotechnology company Contraline is just one of many forms of male contraception currently being tested.

Others contain a hormonal gel that can be rubbed on the shoulders, which is in phase 2b trials in Britain. A similar gel is also being developed by the Parsemus Foundation in India, which would also like to inject a gel into the vas deferens.

For the ADAM study, participants were recruited in Australia and administered the contraceptive during a doctor's appointment that lasted no longer than 15 minutes.

Participants were first given a local anesthetic before doctors made a small incision under the scrotum and exposed part of the vas deferens.

They then injected the tube with the gel before reinserting it into the body and sewing up the incision.

This is similar to a vasectomy, which also addresses the vas deferens – although in this case the tube is cut and doctors warn it is rarely reversible.

There was great interest in the study: more than 1,500 men of various ages applied for the 25 available places.

All participants were then monitored after the gel was injected.

No side effects were reported, and everyone saw a drop in their sperm count, a sign that the contraceptive had worked.

If a person's ejaculate does not contain sperm, it lacks the cells necessary to fertilize an egg and cause a pregnancy.

A new trial is now planned to test whether the contraception can be reversed, with the company aiming to get their contraception through the Food and Drug Administration (FDA) and directly into patients' hands by 2027.

They hope to receive an investigational device exemption from the FDA by the end of this year, allowing clinical trials of the gel to begin in the US.

No details are available on how much the treatment would cost.

Eisenfrats said STAT news: 'Reversibility is a very important value proposition.

'Men want to know that they can have it removed at any time, that their fertility will return to normal and that the recovery procedure is simple.'

He added: “We envision our first product being something that men can get every one or two years.

'Obviously we will do the clinical trials to prove that it is effective over that period of time.'

Some experts have previously raised concerns that the gel could deteriorate over time or that sperm could find a way around it, causing an unplanned pregnancy.

Scientists have been trying to develop an effective contraceptive for men since the 1950s, including pills, gels and injections.

None have been approved, and even the most promising options are still expected to be years away from widespread availability.

A major hurdle is that birth control for women works by preventing ovulation, which happens once a month.

But any male contraceptive would have to interrupt the production of millions of sperm that men make every day.

Most drugs undergoing clinical trials target testosterone, which causes the male sex hormone to block the production of healthy sperm cells.

However, doctors say the testosterone blocking effect can cause weight gain, depression and increase cholesterol. —

By comparison, the female combined contraceptive pill – which contains synthetic versions of the female hormones estrogen and progesterone – has been linked to similar mental health side effects.

Women have several birth control options available, including quick, short-term methods such as birth control pills and patches and a contraceptive cap or diaphragm.

They also have long-term options, such as implants – which produce hormones that stop an egg from being released – or an IUD – or a device placed in the uterus to prevent an egg from implanting.

The birth control pill or patches are about 93 percent effective at preventing pregnancies, while long-term devices such as the IUD are more than 99 percent effective.