While there are plenty of options for female birth control (though none without side effects, and none that are 100% effective), there’s a dearth of options for male birth control—we’re talking condoms or a vasectomy. The onus of birth control has been placed on people with uteruses since, well, forever, and it’s beyond time for that to change.
“Women have many choices for birth control, ranging from pills to patches to intrauterine devices, and partly as a result, they bear most of the burden of preventing pregnancy,” says The American Chemical Society in a press release about the new research. “But men’s birth control options—and, therefore, responsibilities—could soon be expanding.”
Seeking reversible sterility
The goal with any male contraceptive method is essentially to induce temporary or reversible sterility that’s highly effective and with minimal to no side effects. Condoms, as a physical barrier, can fail often, whereas at the opposite end of the spectrum, a surgical vasectomy procedure is considered to be permanent. There has yet to be a viable option to fill that void in between.
But in findings presented at the March 2022 meeting of the American Chemical Society, a team of researchers from the University of Minnesota developed a non-hormonal male contraceptive that works to inhibit sperm production by blocking a receptor that binds vitamin A (retinoic acid).
Vitamin A plays an important role in cell growth, sperm formation and embryonic development. Preventing proteins from binding to a vitamin A receptor (retinoic acid receptor alpha [RAR-α]) can virtually cause sterility by preventing sperm production.
The researchers used the drug on mice, and found that in just four weeks, blocking this receptor caused sterility that was 99% effective at preventing pregnancy—and, notably, without any other obvious side effects. After taking the mice off the drug, sperm production resumed in four to six weeks and the mice could father pups again.
The next step? To study the drug’s effects in human trials.
Aiming to minimize side effects
Targeting the specific vitamin A receptor RAR-α is a new pivot.
Previous studies looking at creating a male contraceptive have typically targeted testosterone, one of the primary sex hormones. But impacting testosterone production can come with more pronounced side effects, like weight gain, depression and increased cholesterol levels.
Because vitamin A isn’t a hormone, the potential for wider-ranging side effects is reduced.
“Scientists have been trying for decades to develop an effective male oral contraceptive, but there are still no approved pills on the market,” says Md Abdullah Al Noman, who presented the work. “We wanted to develop a non-hormonal male contraceptive to avoid these side effects.”
Female hormonal contraceptives, both oral and intrauterine, are of course not without side effects, ranging from spotting, nausea, migraines and depression to lower libido and blood clots, just to name a few. Even a non-hormonal option, like the copper IUD, can cause heavy periods, spotting between periods and cramping.
But because the result of failed contraceptives is a potential pregnancy, people with uteruses tend to have a higher tolerance for side effects from contraceptives—frankly speaking, they’ll put up with more. “Since men do not have to [make the] trade-off between pregnancy and side effects, men are less willing to take a birth control pill that has such significant side effects,” states Noman.
An option on the horizon
The results from the initial research seem promising. “When we went to even 100 times higher dose than the effective dose, the compound didn’t show any toxicity,” says Noman in New Scientist. But mice are not a substitute for humans, and success in animal studies cannot always be replicated in human subjects.
The drug, known as compound YCT529 is licensed with YourChoice Therapeutics, a birth control startup. Human clinical trials are set to start in the third or fourth quarter of 2022. If the trials are successful and the drug is authorized by the Food and Drug Administration (FDA), it could be available for purchase in 5 years.
While that’s still a ways away, experts are optimistic that it’ll happen. And if it does? It will be the first real opportunity to effectively provide reproductive autonomy for all genders—something to celebrate, indeed.