Ultra High Dilutions
In 2007 a systematic review of 67 experiments published in 75 publications evaluated the entire in vitro (test tube) evidence base for the effects of high potency homoeopathic medicines. 75% of these found that ultra high dilutions have effects.
Witt CM, Bluth M, Albrecht H, et al, The in vitro evidence for an effect of high homeopathic potencies - a systematic review of the literature, Complement Ther Med, 2007; 15: 128-138.
Ultra high dilutions under experimental conditions have been shown to have effects such as homoeopathic dilution of histamine altering the activity of white blood cells (Belon P. Crumps J. Ennis M, et al. Histamine dilutions modulate basophil activation, Inflammation Research, 2004; 53: 181-8)
Also homoeopathic thyroxine slowing down the metamorphosis of tadpoles into frogs (Endler PC, Heckmann C, Lauppert E, et al. The metamorphosis of amphibians and information of thyroxine. In: Schulte J, Endler PC (eds). Fundamental Research in Ultra High Dilution and Homoeopathy. Dordrecht: Kluwer Academic Publishers, 1998.)
Dissolved molecules would be expected to spread further and further apart, but chemists Kurt Geckler and Shashadhar Samal in South Korea made a chance discovery. Particles of diluted substances that thy observed clustered together, becoming larger aggregates of those clusters. This could tie in with homoeopathic remedies becoming more powerful despite being more dilute. Read more here.
Research and Surveys
Double blind randomised trials are not ideally suited to testing the efficacy of homoeopathy as each prescription is individualised to match the patient. For example, 15 people with arthritis may all need a different homoeopathic remedy.
However, as at the end of 2009, 142 randomised controlled trials of homoeopathy had been published in peer-reviewed journals. Of these, 63 demonstrate that homoeopathy has a statistically significant effect beyond placebo. 11 are negative and 68 are inconclusive, highlighting the need for more appropriate research methods (e.g. pragmatic trials that test efficacy under real life conditions) and larger scale studies (difficult due to lack of funding).
In November 2005 the Bristol Homeopathic Hospital conducted a study of 6,500 patients receiving homoeopathic treatment, with an overall improvement in health of 70% of participants. Conditions treated ranged from eczema and asthma to menopause symptoms. Many had already tried conventional treatment without success. Read more here.
"I can't manage without homoeopathy. In fact, I never go anywhere without homoeopathic remedies. I often make use of them." Paul McCartney