Cornell researchers achieve first reversible male birth control in mice

Reversible male birth control just cleared a major hurdle: in a new Cornell study, male mice stopped producing sperm entirely after three weeks of treatment, then bounced back to full fertility within six weeks of stopping. The approach skips hormones altogether, targeting a specific window of sperm development in the testis so libido and other traits stay untouched. Even better, the mice went on to father healthy pups who were themselves fertile. The researchers are now testing new molecular targets and hope to launch a company within two years to move toward human trials. If the science holds up across species, it could finally give men a real long-acting option — and ease a contraceptive burden women have shouldered alone for generations.