In the year 2022, male contraception is still basically limited to two options: condoms or vasectomy.
Of course, this isn’t due to a lack of trying. There have been many attempts to curtail male fertility through hormonal contraceptives that decrease sperm production. But just as happens with women who go on the pill, men in clinical trials for similar drugs have experienced side effects like weight gain, acne, mood changes, and (unsurprisingly) a dip in their sex drive.
But what if there was a way to snip your swimmers with a pill without hormones? Scientists might just have the answer.
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In new findings presented at the spring meeting of the American Chemical Society on Wednesday, researchers at The University of Minnesota created a brand new drug, called YCT529, that targets not the male hormone testosterone, but a protein called retinoic acid receptor alpha. Mice that were given the drug in laboratory trials were rendered essentially infertile as sperm counts dropped dramatically. Better yet, this infertility was reversed once the mice were off the pill, and didn’t cause the mice any serious or concerning side effects. The new study opens up the doors for a birth control pill for men that’s incredibly tolerable (i.e. fewer reasons to be hostile to taking it.)
You might have heard of retinoic acid, derived from vitamin A, as the principal ingredient in any wrinkle-banishing super serum. But it’s also vital for fertility and the normal development of sperm. In the body, it binds to a group of retinoic acid receptors to encourage sperm to mature and function properly.
For decades, scientists knew about this molecular relationship after observing that drugs that blocked the binding of retinoic acid to one of its key receptors led to reduced sperm counts in mice, Md Abdullah Al Noman, a UM graduate student involved in the research project, told The Daily Beast.
That research fell off into obscurity until the UM team decided to pick it back up and design their own drug that could emulate this effect. After several years of intense search and constructing over 100 potential drug candidates, the UM researchers struck gold with a compound they called YCT529.
When given to male mice daily for four weeks, YCT529 greatly reduced mice sperm counts and ended up being 99 percent effective at preventing pregnancy (on a par with the pill’s effectiveness in women). It also didn’t appear to upset the mice or cause any toxic effects—an indicator that we humans may also tolerate YCT529 well without falling ill.
And once the researchers discontinued the drug, the male mice were back to fathering pups within four to six weeks—a reversal that makes this drug all the more attractive.
This could be the best hope yet for a male birth control pill. YCT529 still has to run through the clinical trial gauntlet before it can hit the market, but that may not be too far away. “YCT529 is the furthest ahead of all contraceptive agents for men,” Gunda Georg, a medicinal chemist at UM who led the new study, told The Daily Beast. “We’re really excited about it and we were able to license it to a company, YourChoice Therapeutics.” Clinical trials could start before the year is over, though Georg thinks next year is more likely.
Georg and Al Noman think the new findings could open the door for other non-hormonal birth control drugs that operate in other ways, such as slowing down sperm movement. The real crux of the matter, they said, is to make safe options that encourage men to take birth control while removing the reproductive burden from women.
“Birth control is a critical health-care issue,” Al Noman said. “Because about more than half of all pregnancies in the U.S. are unintended pregnancies. And that can lead to very poor outcomes, whether in terms of the child’s health or maternal health and also financial and career advancement of women. We need to have more investment in the research and development of the male birth control pill.”
