Behold, Birth Control Gel for Guys

A novel birth control option for men, as easy as applying lotion once per day, appears to be effective within weeks with minimal side effects to boot, according to new research. NES/T, a hormonal solution to block sperm production, is applied to the shoulders once per day. One of 222 participants in a phase 2 trial tells NBC News the gel solution felt much like hand sanitizer. Applying it was "such an easy process," the man says, adding the only possible side effects he experienced were acne and minor weight gain. In terms of participants' sperm counts, 20% were sufficiently suppressed within five weeks, 52% by eight weeks, 62% by nine weeks, and 86% after 15 weeks, according to data presented Sunday at the Endocrine Society's conference in Boston, per Gizmodo.

Developed by researchers at the National Institutes of Health's Contraceptive Development Program, NES/T gets its name from its two main ingredients: nestorone and testosterone. Nestorone, a synthetic version of progesterone, lowers the levels of hormones responsible for fertility, including testosterone, in the blood and testes. Since this may reduce a man's sex drive, testosterone is added to the gel "to maintain stable hormone levels in men's blood, ensuring temporary sterility and minimizing side effects," per Gizmodo. "We're pretty pleased with the limited side effects that we have observed," Diana Blithe, chief of the NICHD's Contraceptive Development Program, tells the outlet. She was also pleasantly surprised to see sperm counts fall so quickly.

Researchers consider suppression effective for contraception to be no more than 1 million sperm per millimeter of semen, down from 15 million to 200 million per milliliter, per NBC. The median suppression time was eight weeks. But as many participants weren't checked between weeks four and eight, the true median might be lower. "We're really pleased with this result. And we think it will make the gel more attractive to people who maybe didn't want to wait three months for it to reach its effectiveness," Blithe tells Gizmodo. The research team has since launched a Phase 2B trial involving 400 men, with encouraging preliminary results, ahead of plans for a Phase 3 trial, to be discussed with the FDA next year. If all goes well, the gel could hit the market by the end of the decade, the BBC reports. (More male birth control stories.)