A first-of-its-kind male birth control pill just cleared its first human safety test, raising hopes that it could soon open the door to a new era of contraception.
The drug, YCT-529, is currently enrolled in a larger clinical trial, with experts hoping it’ll be ready to hit the shelves by the end of the decade. Here’s everything you need to know about this potential pregnancy game-changer.
Unlike traditional birth control pills that disrupt hormones, this experimental pill from YourChoice Therapeutics temporarily halts sperm production without affecting testosterone levels.
It works by blocking a protein called retinoic acid receptor alpha, which plays a key role in the sperm making process.
The best part: Early evidence suggests it’s totally reversible.
In tests on male mice, YCT-529 sharply reduced sperm production, causing reversible infertility within just four weeks.
When treated males mated with females, the drug proved 99% effective at preventing pregnancy.
Similar results were seen in male nonhuman primates, whose sperm counts dropped within two weeks of starting treatment.
Notably, both animals fully regained fertility after stopping the drug, with mice recovering within six weeks and primates within 10 to 15 weeks.
No side effects were reported in either group.
The first human trial testing the drug involved 16 healthy men between 32 and 59 — all of whom had previously undergone vasectomies, a surgical procedure that cuts and blocks the tubes that carry sperm from the testicles to prevent pregnancy.
This extra precaution was necessary because no nonhormonal male contraceptive had ever been tested in humans before. Researchers wanted to avoid any risk of permanently affecting fertility, just in case participants wanted to father children later, Nadja Mannowetz, co-founder and chief science officer of YourChoice Therapeutics, told Scientific American.
The goal wasn’t to test effectiveness but to see if the drug was well tolerated and to measure how it built up in the body, she explained.
After testing multiple doses, researchers didn’t find any concerning side effects, including no changes in heart rate, hormone levels, inflammation, sexual function or mood.
That’s notable, because hormonal contraceptives have previously been linked to side effects like mood swings, libido loss, weight gain and acne.
Across all doses, scientists also “saw good and quick bioavailability,” meaning the drug stayed active in the body without breaking down too fast, Mannowetz noted.
