A step towards a pill for men?
How often does locker-room talk involve nuanced discussion of the various types of contraceptives available, and the merits and difficulties associated with them all?
In women's locker rooms, the answer is "surprisingly frequently".
In men's, "hardly ever".
Contraception has long been an overwhelmingly female issue.
At least in part, that is because men have little to discuss.
Their choice is between condoms and vasectomy.
Women, by contrast, may pick from a range which includes the Pill, vaginal rings, copper intrauterine devices, hormonal intrauterine devices, contraceptive sponges, cervical caps, spermicides, diaphragms, female condoms and tubal ligation.
For decades, therefore, researchers have hunted for ways to level the playing field by extending men's options.
But none of the resulting injections, gels and hormonal pills has so far advanced beyond clinical trials.
Jochen Buck and Lonny Levin, who work at Weill Cornell Medicine, in New York, have now entered a new runner into the race.
Their candidate, rather than requiring the consistent and long-term application associated with pills and gels, is fast-acting and temporary.
In a paper published in Nature Communications they show that, in mice at least, it works within half an hour, rendering the animals temporarily infertile by stopping their sperm swimming, but with no perceptible changes in their behaviour or sexual performance.
Importantly, within a day, their fertility returns.
The substance concerned, TDI-11861, belongs to a class of molecules called soluble adenylyl cyclase (sAC) inhibitors.
SAC itself is found in nearly every body cell.
It is a source of a messenger molecule called cAMP, and its activity is regulated by bicarbonate ions.
A preponderance of those ions speeds up the rate at which sAC produces camp.
A dearth slows it down.