The possibility of a male birth control pill may be creeping ever closer.
Scientists have discovered a small molecule that produces a rapid and reversible decrease in sperm count in mice, according to researchers with the Dana-Farber Cancer Institute and Baylor College of Medicine.
The compound, known as JQ1, penetrates a boundary in the cells of the male testes and shuts off sperm development in the testicles. The result is non-hormonal birth control that researchers said is entirely reversible.
"Within one to two months [after discontinuing the drug], there was complete restoration in testicular size, sperm number, sperm motility and -- importantly -- fertility," said Dr. James Bradner, an oncologist with Dana Farber and an author on the study. "The litter size was normal, and there were no obvious, adverse symptoms in these animals."
In the new study, published in the journal Cell on Tuesday, researchers showed how JQ1 effectively penetrated the blood-testis boundary in mice, preventing sperm from maturing. Experts at Dana Farber originally created the compound to block certain cancer-causing genes, but reached out to male contraceptive specialists at Baylor when they began to wonder if it also could be a form of birth control for men.
"It's a very exciting study, particularly from the standpoint that one of the large hurdles that has existed for a long time [is] ... the sperm-generating cells are behind the blood-testis barrier," said Dr. Joseph Tash, director of the Interdisciplinary Center for Male Contraceptive Research and Drug Development at the University of Kansas Medical Center, who did not work on the new study.
"To get a drug across that barrier has been a long, long challenge," he said.
Tash and his team in Kansas are working to develop a different male birth control pill, testing a non-hormonal contraceptive agent known "gamendazole," which also interrupts sperm maturation. It is closer to becoming a viable option on the drug market, having been tested in rodents, rabbits and primates. Tash said the next step is to approach the Food and Drug Administration about starting clinical trials in humans.
Just how far off an option for men truly is, remains a guessing game. At several points in the last decade, media outlets have heralded the possibility that one is on the immediate horizon.
An estimate often bandied about by scientists working in the area is five to 10 years, said Elaine Lissner, director of the Male Contraception Information Project, an advocacy organization that aims to promote awareness about promising non-hormonal male birth control options.
"For the general public, that should be read as 'maybe never'," Lissner said. "It's five to 10 years if everything works, and if we miraculously get a whole bunch of funding."
However the field tends to be collaborative, she said, which can help promote advancement.
“You have to have a number of different options,” said Dr. Ajay K. Nangia, an associate professor of urology at the University of Kansas. “You’d like [your compound] to be the leading contender -- the golden egg -- but the more pathways, the better."
Just as some women prefer or can only tolerate certain birth control options, men would probably benefit from a choice.
But Lissner said that in the last few years, the focus in male contraceptive research has shifted away from hormonal options and toward non-hormonal agents. Last spring, a major trial of hormone-based male contraception was called off early because of the high frequency of bad side effects, including depression.
JQ1, Bradner told The Huffington Post, could cause side effects that are tolerable when it is being used to fight cancer, but would be unacceptable in otherwise healthy men who desire contraceptive control. He cautioned that though the new findings are promising, they are also preliminary.
"It will take some years of research," he said. "It's just completely unpredictable. But we're working very hard on this problem."