Women have long shouldered the responsibility of birth control, using pills, rings, IUDs and more, but the medical tide may be shifting. ABC News reports that a birth-control option for men in the form of a pill called JQ1 reduces sperm production in men. As with birth control used by women, the effects are reversible when the patient is ready to have children.

"We have only observed full recovery of fertility in treated males," the researchers from Baylor College of Medicine wrote in their study, published today in the journal Cell. "We envision that our discoveries can be completely translated to men, providing a novel and efficacious strategy for a male contraceptive."

JQ1 blocks a protein essential for sperm production in the testes. If the drug is proven to be safe and effective in humans, it could expand the prophylactic pool — an exciting prospect at a time when over a third of U.S. pregnancies are unintended.

But some doctors say the idea of slashing sperm counts, even temporarily, can be scary for guys.

"Sperm-making is a pretty delicate thing, and people do seem to have a concept of that," Dr. Joseph Alukal, director of male reproductive health at New York University's Langone Medical Center, told ABCNews.com.

Read more at ABC News.