The American National Institutes of Health (NIH) has announced its plan for a clinical trial to take place to evaluate the efficacy of a male contraceptive gel.

The topical gel is set to be trialled by couples at sites across the globe with scientists based in Los Angeles and Seattle heading up the research.

How does the gel work?

The gel known as NES/T contains a combination of a progestin compound known as segesterone acetate, which has the brand name Nestorone, and testosterone.

The gel is applied to the back and shoulders where it is absorbed through the skin. The progestin works to block the normal testosterone production that occurs in the testes, and by doing so it reduces the sperm count to a very low or undetectable level.

The testosterone in the gel works to replace the testosterone that is no longer being produced by the testes. This allows the male user to maintain their testosterone levels so that other functions, such as sex drive, are not altered.

How will the trial take place?

The researchers are setting out to recruit 420 couples into the trial.

The men will initially use the gel for between four to 12 weeks to assess tolerability. Sperm levels will be monitored to see if they have declined to within the threshold set for contraception purposes. This period may be extended to 16 weeks, if further time is required.

At this point, if sperm levels have dropped sufficiently, the participants will enter the efficacy period where researchers will be assessing the performance of the gel at preventing pregnancies. This assessment period will last for 52 weeks and the gel will be used as the sole contraceptive method.

The male participants will remain under observation for study purposes for 24 weeks after the trial has stopped.

Why are male contraceptives being researched?

Male contraception is currently limited to condoms or a permanent vasectomy operation. There has long been a void for a safe, effective and easily reversible male contraceptive.

Women have several contraceptive options to consider but not all of them provide suitable options depending on each user’s different circumstances. Some women are unable to tolerate the current contraceptives on offer.

One of the main difficulties researchers face when looking into male contraceptives is the reversibility factor. The contraceptive needs to offer convenient pregnancy prevention but it should be easily reversible once treatment use is stopped.

Researchers are hopeful that the at-home, topical gel method will appeal to potential male users.

It is not clear when the results of the study will be available or how long it will take for this product to hit the market if it proves successful. However, the research being carried out offers new hope for men looking to take control of their reproductive health.