Homeopathic remedies do not provide any specific effects and are in fact, no better than placebos, the results of a new study indicate.

Homeopathy is based on the theory 'like cures like' - that a substance which causes symptoms should also relieve them. Homeopathic remedies are extremely diluted solutions (usually one part per million or less) of assorted herbs, animals products and chemicals.

The remedy therefore contains little, if any, of the original substance but according to homeopathic practitioners, the solutions continues to hold a 'trace memory' of the original substance that can mobilise the body's 'vital forces'.

Conventional medicine has long held the view that any relief is coincidental or is down to the placebo effect. (Placebos are harmless substances or 'dummy' drugs.)

A team of British and Swiss researchers carried out an extensive review of 110 trials involving homeopathy. All of the trials looked at homeopathy, placebos and conventional medicine and included conditions such as asthma and allergies.

The researchers found that homeopathic remedies were no better than placebos.

"The evidence for a specific effect of homeopathic remedies is weak...there was no convincing evidence that homeopathy was superior to placebo, whereas for conventional medicine, an important effect remained", they said.

Details of their findings are published in the medical journal, The Lancet.