Science author Simon Singh and a professor of complementary medicine at the University of Exeter named Edzard Ernst have put up a £10,000 bounty to anyone who can show that homeopathic remedies work better than placebos.
The pair are not against complementary remedies. Of those examined in their book, 36 worked for particular conditions – such as St John's wort for mild depression – but homeopathy was not among them.
Homeopaths seem in no hurry to take up the offer. "We have nothing to prove, and certainly not to people with closed minds," says Steve Scrutton of the Alliance of Registered Homeopaths.