Pause-and-resume sperm strategy edges closer to reversible male birth control

A Cornell University study in mice shows that sperm production can be paused by targeting a meiosis checkpoint using the molecule JQ1, stopping sperm development and then resuming after stopping the drug; fertility returns and offspring are healthy, suggesting a nonhormonal, reversible path toward long-acting male contraception in the future, though it is not consumer-ready and currently involves a drug with neurological side effects.