might suggest otherwise. "Whenever there's a study published, a radio journalist will walk up and down the high street in their local town and ask women whether they'd trust a man to take a pill, and of course they all run for the hills. But if you ask a woman if they would trust their partner, who they share children, their bank account, and a bed every night with, then you're going to get a different answer."

In 1995 and 1996, researchers including Anderson interviewed 1,829 men across four cities: Edinburgh, Cape Town, Shanghai and Hong Kong. White men in Cape Town were most eager, with four-fifths saying they would at least probably use a male hormonal contraceptive pill. Hong Kong residents were least keen, with two-fifths saying thatbrain making luteinizing hormone and follicle-stimulating hormone. The absence of these hormones stops the man's testicles producing sperm – but it also stops them producing testosterone. So testosterone replacement is given along with progestogens, to avoid undesirable effects like weaker muscles and lessened sex drive.

The Edinburgh scientists' various trials have long attracted media attention. "'100% success' for male pill trial," trumpeted the BBC in 2000, reporting on the suppression of sperm production in 30 men – reportedly without side-effects – from a combined progestogen pill and testosterone-releasing implant. Both hormones came from the Dutch drug company Organon, which, after what Anderson calls "a lot of persuading", began to pay attention.

Eventually Organon teamed up with Germany's Schering on a larger clinical trial in 2003–04. Researchers gave 297 men progestogen