Reviewers conducted heroic searches including the main databases, specialist journals, manufacturers of homeopathic remedies, and drug regulatory agencies in the USA and UK, and experts in the field were contacted. Published reports were assessed for quality and a judgement made by the reviewers on the causation of the AE reported. The mean number of patients reporting at least one adverse effect with homeopathy was 9.40 and with placebo 6.17 in a total of 12 trials. The adverse effects were mild and transient in nature. Perhaps more striking is the fact that 36 reports did not report on collection or incidence of adverse effects at all.
Case reports Very few case reports described adverse effects.
Those that were reported tended to be symptoms described as aggravation of the pre-existing symptoms.