The Lancet says the time for more studies is over and doctors should be bold and honest with patients about homeopathy's "lack of benefit".

A Swiss-UK review of 110 trials found no convincing evidence the treatment worked any better than a placebo.

Advocates of homeopathy maintained the therapy, which works on the principle of treating like with like, does work . . .

. . . According to Professor Matthias Egger, from the University of Berne, and Swiss colleagues from Zurich University and a UK team at the University of Bristol, homeopathy has no such evidence.

They compared 110 trials that looked at the effects of homeopathy versus placebo with 110 trials of conventional medicines for the same medical disorders or diseases.

This included trials for the treatment of asthma, allergies and muscular problems, some large and some small.

For both homeopathy and conventional medicines, the smaller trials of lower quality showed more beneficial treatment effects than the larger trials.

However, when they looked at only the larger, high-quality trials, they found no convincing evidence that homeopathy worked any better than placebo.

Professor Egger said: "We acknowledge to prove a negative is impossible.

"But good large studies of homeopathy do not show a difference between the placebo and the homeopathic remedy, whereas in the case of conventional medicines you still see an effect."