Male birth control could be a reality soon
For as long as birth control has existed, the onus has been on the person who can become pregnant. While technology has come a long way since the ancient days of using crocodile dung and lead or mercury as contraceptives, the responsibility remains one-sided. Condoms exist, of course, as do vasectomies, but there’s been no equivalent to the pill for men. That might change soon, with a male birth control pill potentially heading for human trials by the end of this year.
Researchers at the University of Minnesota are working on a compound they call GPHR-529 that could be a breakthrough in male birth control. We know that vitamin A is critically important to fertility in mammals, so the idea behind GPHR-529 is to block a protein that binds to a form of vitamin A in human cells. This blockage would lower sperm count enough to cause temporary sterility.
In trials on mice, GPHR-529 proved 99% effective in preventing pregnancy. Four to six weeks after the researchers stopped giving male mice GPHR-529, they were fertile again. Should this prove the same in humans, rather than going to the lengths of having a vasectomy reversed (a procedure with a 90-95% efficacy rate), men could simply stop taking the pill for a few weeks if they’re trying to impregnate their partner.
Unlike Nestorone, a contraceptive that lowers testosterone and sperm count, GPHR-529 is non-hormonal. This means little to none of the common side effects of low testosterone — weight gain, depression, and elevated LDL cholesterol. The mice in the trials didn’t show any adverse effects.
“When we went to even 100 times higher dose than the effective dose, the compound didn’t show any toxicity,” Md Abdullah al Noman, one of the researchers, told New Scientist.
That all sounds great, but there have been decades of attempts at effective oral male birth control with nothing on the market yet. And, as Noman concedes, clinical trials are the test of safety. What worked in mice may or may not work in men.
“Because it can be difficult to predict if a compound that looks good in animal studies will also pan out in human trials, we’re currently exploring other compounds, as well,” Gunda Georg, head of the University of Minnesota’s department of medicinal chemistry said in a press release.
In the meantime, the researchers have licensed GPHR-520 to YourChoice Therapeutics — for which Georg serves as a consultant — and early-stage clinical trials in humans could start this year.
As for Nestorone, the National Institute of Child Health and Human Development has been conducting trials on NES/T, a gel men can rub into their shoulders and upper arms. The NICHD says that clinical studies have shown successful sperm suppression with minimal side effects. Phase 2 clinical trials are set to be completed in 2023.
The University of Edinburgh conducted a study of 100 men using NES/T in 2021.
“Patient satisfaction in using the gel seems high,” Dr. Babak Ashrafi told The Telegraph. “But there might still be a significant proportion of men who would find application of a gel (which takes time to dry) cumbersome. Also, as a new drug, long-term outcomes are yet to be fully understood. That’s something which might give clinicians as much hesitation as patients.”
Potential Societal Impact
Until male birth control is widely available, we won’t really know the extent of its effects on society. We do know that the introduction of a birth control pill for women in 1960 had a profound effect on birth rates, average age of marriage, and levels of education and employment for women. A lot of that impact is already cemented into society, though. Would the availability of male birth control change things anywhere near as much?
To answer that question, you’d have to know how many men would use birth control. When it comes to vasectomies, about 9% of sexually active American men get vasectomies, as compared to 27% of sexually active American women who have tubal ligation. Vasectomies are 99.99% effective and take only about 10 minutes, with local anesthetic. Recovery time takes only a few days. Still, there are some barriers to uptake. Some are psychological, as there are men who don’t want to lose their sense of virility. There are also more practical considerations. As mentioned, while vasectomies can be reversed, reversal doesn’t take 5-10% of the time. They can also cost $1,000 or more in the U.S. — in Canada (33%) and New Zealand (50%), where vasectomies are covered under universal healthcare, uptake rates are much higher. If insurance treated male birth control the same as pills for women, they’d cost anywhere from $15 to $50 a month.
However you slice it, taking a pill seems a lot easier than getting a vasectomy. For long-term committed couples who don’t want children, don’t want any more children, or don’t want more children for a while, the prospect of the male partner taking birth control could be a welcome alternative to female contraception options that come with a host of side effects. As for single men and those in casual relationships, how many would take a birth control pill? Would their female partners trust that they’re taking it regularly, or would they continue taking theirs? Even with male birth control readily available, the consequences of pregnancy will always have a greater effect on the person who might get pregnant.