A contraceptive gel for men is set to undergo an international test run in 2018. Scientists have been aiming to develop male birth control that can go into market within the next decade.
The clinical trial, sponsored by the National Institutes of Health and the Population Council, will begin during the first half of 2018. The test will involve 400 couples from the U.S., Chile, Italy, Kenya, Sweden and the United Kingdom, Time reports.
Female partners will be asked to take birth control during the first four months of the trial. After that, the couples will be required to only use the male contraceptive for an additional year.
The male contraceptive consists of a gel men can rub into their arms and shoulders on a daily basis. The gel is designed to lower the man's sperm count for up to 72 hours by suppressing the testosterone in his testes with the chemical nestorone. The resulting hormonal imbalances would be offset by a synthetic testosterone that does not spur sperm production.
Dr. Min Lee of the National Institute of Child Health and Human Development, who is spearheading the trial, said that a key goal of the test is to determine the best combination of nestorone and synthetic testosterone.
"If we stop the production of testosterone, men are obviously going to experience side effects beyond just their sperm count," Lee explained.
In 2016, a clinical trial that utilized nestorone and synthetic testosterone showed a 96 percent success rate in suppressing sperm but also resulted in unpleasant side effects for test subjects. Patients reported that they experienced mood swings and muscle pain.
Lee said that the latest study would lower the dose of synthetic testosterone.
"We're only adding back just enough so they have normal physiological responses, not the huge amount that's been used in other formulations," Lee said.
Lee added that if the trial was successful, it would still take at least five years before the contraceptive received government approval and was allowed into the market.
Female contraceptives are a $10 billion industry, while condom sales worldwide total $3.2 billion each year. Birth control experts say that major pharmaceutical companies are not interested in exploring male birth control.
"The fact that the big companies are run by white, middle-aged males who have the same feeling -- that they would never do it -- plays a major role," gynecology professor Herjan Coelingh Bennink told Bloomberg. "If those companies were run by women, it would be totally different."
For instance, Indian professor Sujoy Guha has developed an injection that reversibly makes men sterile. While Guha's contraceptive is said to be medically viable, he has not found interest from pharmaceutical companies.
"In doing anything abroad, quite substantial money is required, and that can only come from the pharmaceutical industry," Guha said.
Male Contraception Initiative Executive Director Aaron Hamlin predicted that the likeliest scenario for male birth control becoming prevalent was if a viable product was developed by a nonprofit or small company and was then licensed by a large distributor.
"Pharmaceutical companies are looking to minimize risk while opening themselves up to large profits ... pharmaceutical companies may look more seriously [into licensing the technology or acquiring the company]," Hamlin told CNBC.