Homeopathy 2010; 99(01): 76-82
DOI: 10.1016/j.homp.2009.11.002
Copyright © The Faculty of Homeopathy 2009

Placebo effect sizes in homeopathic compared to conventional drugs – a systematic review of randomised controlled trials

Tobias Nuhn
1  Klinik Roderbirken, Roderbirken 1, 42799 Leichlingen, Germany
Rainer Lüdtke
2  Karl und Veronica Carstens-Stiftung, Am Deimelsberg 36, 45276 Essen, Germany
Max Geraedts
3  Institut für Gesundheitssystemforschung, Private Universität Witten/Herdecke gGmbH, Alfred-Herrhausen-Straße 50, 58448 Witten, Germany
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Further Information

Publication History

Received23 July 2009
revised20 October 2009

accepted02 November 2009

Publication Date:
20 December 2017 (online)

Background: It has been hypothesised that randomised, placebo-controlled clinical trials (RCTs) of classical (individualised) homeopathy often fail because placebo effects are substantially higher than in conventional medicine.

Objectives: To compare placebo effects in clinical trials on homeopathy to placebo effects on trials of conventional medicines.

Methods: We performed a systematic literature analysis on placebo-controlled double-blind RCTs on classical homeopathy. Each trial was matched to three placebo-controlled double-blind RCTs from conventional medicine (mainly pharmacological interventions) involving the same diagnosis. Matching criteria included severity of complaints, choice of outcome parameter, and treatment duration. Outcome was measured as the percentage change of symptom scores from baseline to end of treatment in the placebo group. 35 RCTs on classical homeopathy were identified. 10 were excluded because no relevant data could be extracted, or less than three matching conventional trials could be located.

Results: In 13 matched sets the placebo effect in the homeopathic trials was larger than the average placebo effect of the conventional trials, in 12 matched sets it was lower (P = 0.39). Additionally, no subgroup analysis yielded any significant difference.

Conclusions: Placebo effects in RCTs on classical homeopathy did not appear to be larger than placebo effects in conventional medicine.