Why Isn't There a Male Birth Control Pill?

Female hormonal contraceptives gave women unprecedented control over their reproductive health with the approval of the pill on June 23, 1960. But a similar male version has never reached the market. Physiological differences between men and women’s reproductive cycle, along with economic and regulatory problems, have stood in the way of a male pill for 50 years, scientists say.

The main difference between designing a contraceptive for men, as opposed to one for women, is the number of reproductive cells that the pill would need to stop, said John Amory, associate professor of medicine at the University of Washington Medical Center in Seattle. Whereas a pill for women only needs to prevent the release of a single egg once a month, a pill for men faces a larger, constant challenge.

“People have been trying to develop a male analog to the pill ever since the female pill came out. Turns out its much more difficult,” Amory told Life’s Little Mysteries. “The biological barriers are nontrivial. Women produce one egg a month, and men produce 1,000 sperm per second. It's much harder to stop that higher production system.”

Preventing sperm creation involves supplementing the body’s natural hormone production with testosterone delivered through medicine. With an external source of testosterone, the testes stop producing the hormone. While medicine would keep the body's overall testosterone concentration at healthy levels, the loss of local production in the testes stops sperm generation.

Another obstacle is the policy of the Food and Drug Administration (FDA), said Christina Wang, a professor of endocrinology at UCLA Medical Center. While hormone therapy might work well in most men, it may still fail to produce effective contraception in a high enough percentage of men for drug companies to feel confident that the medication will gain FDA approval, Wang said. Without that confidence, pharmaceutical companies won’t spend the money needed to develop the drug, Wang said.

“The female contraceptive pill was associated with significant side effects during its first few years of use, including some fatalities. The FDA of 1960 is not the FDA of today,” Amory said.

Additionally, the male “pill” couldn’t be a pill at all. The liver breaks down testosterone so quickly that orally-taken testosterone contraceptives don’t work, Amory said. Instead, the medication would need to take the form of an injection or a cream, which consumers find less attractive than a pill, Amory said.

Many of these hurdles have proven insurmountable for the decades, and show no sign of abating in the near future.

“People have been saying we're going to have a male contraceptive in five to 10 years, for the last 30 years,” Amory said. “I've had people say 'call me when you have something that's oral, once a day, 95% effective and has no side effects.’”

This article was provided by Life’s Little Mysteries, a sister site to LiveScience.