'Homeopathy': untangling the debate

There are active public campaigns both for and against homeopathy, and its continuing availability in the NHS is debated in the medical, scientific and popular press. However, there is a lack of clarity in key terms used in the debate, and in how the evidence base of homeopathy is described and interpreted. The term 'homeopathy' is used with several different meanings including: the therapeutic system, homeopathic medicine, treatment by a homeopath, and the principles of 'homeopathy'. Conclusions drawn from one of these aspects are often inappropriately applied to another aspect. In interpreting the homeopathy evidence it is important to understand that the existing clinical experimental (randomised controlled trial) evidence base provides evidence as to the efficacy of homeopathic medicines, but not the effectiveness of treatment by a homeopath. The observational evidence base provides evidence as to the effectiveness of treatment by a homeopath. We make four recommendations to promote clarity in the reporting, design and interpretation of homeopathy research.