OBJECTIVE:

To evaluate the evidence for and against the effectiveness of homeopathy.

DATA SOURCES:

The Cochrane Database of Systematic Reviews (generally considered to be the most reliable source of evidence) was searched in January 2010.

STUDY SELECTION:

Cochrane reviews with the term "homeopathy" in the title, abstract or keywords were considered. Protocols of reviews were excluded. Six articles met the inclusion criteria.

DATA EXTRACTION:

Each of the six reviews was examined for specific subject matter; number of clinical trials reviewed; total number of patients involved; and authors' conclusions. The reviews covered the following conditions: cancer, attention-deficit hyperactivity disorder, asthma, dementia, influenza and induction of labour.

DATA SYNTHESIS:

The findings of the reviews were discussed narratively (the reviews' clinical and statistical heterogeneity precluded meta-analysis).

CONCLUSIONS:

The findings of currently available Cochrane reviews of studies of homeopathy do not show that homeopathic medicines have effects beyond placebo.