Gel
A pump bottle of gel for representational purpose only

Aside from condoms and a vasectomy, men could soon have a new birth control option in a form of a gel. Starting April 2018, government researchers in the US will be testing out a contraceptive gel for men which is said to prevent the production of sperm.

More than 400 couples from the US, the UK, Italy, Kenya, Sweden and Chile are set to go on a four-month clinical trial for this unconventional birth control method, which has been studied for more than a decade. Two synthetic hormones--testosterone and a form of progestin--form the gel.

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Progestin prevents the testes from making enough testosterone to produce the substantial amount of sperm. The stand-in testosterone is necessary to curb the hormone imbalances the progestin causes but will not make the body produce sperm. Male participants will rub about half a teaspoon of the gel on their upper arms and shoulders on a daily routine.

In an interview with Technology Review, Régine Sitruk-Ware, distinguished scientist at the Population Council, a nonprofit for reproductive health, notes that the gel can hold off sperm levels for approximately 72 hours. So in case of participants forget a dose, they still have enough leeway. Meanwhile, partners of the participants will also use some form of female contraception.

Men's sperm count will be monitored by researchers. According to Diana Blithe, program director for contraception development at the National Institute of Child Health and Human Development, under the NIH, sperm levels should decrease to less than a million per millilitre to effectively prevent pregnancy.

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Once sperm count goes low enough, female counterparts will stop using their contraceptive and then use the male contraceptive gel as the only birth control for a year. If the trial succeeds, Blithe admits it could take few years before the gel would be available to the public.

The Population Council and the US National Institute of Health (NIH) are the primary sponsors of the clinical trial, which will run for at least four months from April 2018.