When it comes to contraceptives, men and women have quite different options. For women, the choices vary from hormonal contraceptive pills, to IUDs, to shots to patches. For men, on the other hand, there is simply the condom. And for many years, science has failed to crack the male contraceptive mystery. But a new study in Cell has uncovered a tiny molecule that might change all that.
The problem in making a male contraceptive is pretty simple. John Amory, a doctor at the University of Washington, summed up the issue to Popular Science this way: "Women make one egg a month, but men make 1,000 sperm every second of every day, from puberty until the day they die. Turning that off is difficult."
But today, in the journal Cell, researchers prove that they can generate reversible birth control in male mice. Here's how it works, according to the press release:
The compound, called JQ1, penetrates the blood-testis boundary to disrupt spermatogenesis, the process by which sperm develop to become mature sperm. The result is a decrease in the number and quality of sperm. The study showed that normal sperm production resumed when JQ1 was discontinued, and JQ1 did not affect testosterone production, mating behavior, or the health of offspring conceived after JQ1 use.
Basically, they could stop male mice from making sperm while they were on the drug, and then get them to make sperm again once the mice were taken off of it. The ability to return to normal after using the drug has been a key roadblock in creating a male contraceptive.
A few months ago researchers unveiled developments in a male contraceptive lotion that uses hormones to reduce sperm production. Another recent advance in genetics could provide a different way for men to keep their sperm at bay. Researchers call it a "genetic vasectomy" and it works by blocking the gene that produces sperm. The benefits of a genetic approach are many, says the Daily Mail:
As it wouldn't be based on hormones, it shouldn't disrupt a man's sex drive. And, unlike some other hormone-based male contraceptives in development, it should be free of other unwelcome side-effects such as mood swings and hot flushes.
But even with these chemicals and therapies that stop sperm production, there are significant challenges. Discovery writes:
For starters, hormones fail to adequately suppress sperm production in up to 20 percent of men, and scientists have no way of knowing which men will fall into that group.
There are also side effects, including acne, weight gain and a 10 percent drop in good cholesterol levels, as well as a shrinking of the testes by 25 percent -- which, Amory insisted, men don't usually notice.
And there is the eternal question of whether men will use a contraceptive if its provided to them. Surveys suggest about half of men are interested, but Amory thinks it's probably higher. "Men are often interested in having sex and not being fathers," Amory told Discovery. "If they had an option, I think many of them would embrace it."