Scientific Research

Homeopathy – What are the active ingredients? An exploratory study using the UK Medical Research Councils framework for the evaluation of complex interventions

Medical Research Councils framework for the evaluation of complex interventions

1 Academic Unit of Primary Care, Cotham House, Cotham Hill, Bristol BS6 6JL, UK
2 Department of Pharmacy and Pharmacology, University of Bath, UK

BMC Complementary and Alternative Medicine 2006, 6:37doi:10.1186/1472-6882-6-37

The electronic version of this article is the complete one and can be found online at:

Published: 13 November 2006

© 2006 Thompson and Weiss; licensee BioMed Central Ltd.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.



Research in homeopathy has traditionally addressed itself to defining the effectiveness of homeopathic potencies in comparison to placebo medication. There is now increasing awareness that the homeopathic consultation is in itself a therapeutic intervention working independently or synergistically with the prescribed remedy. Our objective was to identify and evalute potential “active ingredients” of the homeopathic approach as a whole, in a prospective formal case series, which draws on actual consultation data, and is based on the MRC framework for the evaluation of complex interventions.


Following on from a theoretical review of how homeopathic care might mediate its effects, 18 patients were prospectively recruited to a case series based at Bristol Homeopathic Hospital. Patients, who lived with one of three index conditions, were interviewed before and after a five visit “package of care”. All consultations were recorded and transcribed verbatim. Additional data, including generic and condition-specific questionnaires, artwork and “significant other” reports were collected. Textual data was subject to thematic analysis and triangulated with other sources.


We judged that around one third of patients had experienced a major improvement in their health over the study period, a third had some improvement and a third had no improvement. Putative active ingredients included the patients’ “openness to the mind-body connection”, consultational empathy, in-depth enquiry into bodily complaints, disclosure, the remedy matching process and, potentially, the homeopathic remedies themselves.


This study has identified, using primary consultation and other data, a range of factors that might account for the effectiveness of homeopathic care. Some of these, such as empathy, are non-specific. Others, such as the remedy matching process, are specific to homeopathy. These findings counsel against the use of placebo-controlled RCT designs in which both arms would potentially be receiving specific active ingredients. Future research in homeopathy should focus on pragmatic trials and seek to confirm or refute the therapeutic role of constructs such as patient “openness”, disclosure and homeopathicity.


Homeopathic medicine continues to attract attention in medical journals and the media as a popular form of complementary medicine (CM) whose proposed mechanism of action seems incompatible with mainstream scientific thought and the research evidence for which remains controversial. At the centre of clinical research in into homeopathic medication lies the placebo controlled randomised clinical trial (RCT). RCT findings for homeopathic medications are heterogeneous and meta-analytical approaches have reached both positive [1] and negative conclusions [2].

An assumption underlying RCT-based research is that homeopathic medicines can be considered as a special class of pharmaceutical agent with specific effects. When, as in the Shang et al meta-analysis,[2] the therapy is presented as having no specific effects, it is considered to be mediated by “non-specific” effects. An intervention based solely on such effects is considered of little value – the editor of the Lancet proposing that Shang’s findings heralded the “end of homeopathy”. But despite these condemnations, homeopathic care remains popular, a fact which some accord to the empathic style of homeopathic practitioners.

The RCT model is only one possible way of approaching the riddle of homeopathy – other include in vitro studies [3] and large-scale observational studies [4-7]. In this study we consider it not as a pharmaceutical intervention, but as a complex intervention and have analysed its active ingredients using a framework proposed by the UK Medical Research Council (MRC) [8]. This treatment is justified because the homeopathic approach contains “a number of components which may act both independently and interdependently” – the criterion for the definition of a complex intervention. For instance consultations involve the patient in an unusually detailed exposition of their complaints, an attentive practitioner and a process of matching between the patient’s predicament and what is known of a wide range of homeopathic medicines. Thus even on prima facie grounds there are a number of potential factors at play.

The first stage of the MRC framework asks the investigator to explore how a given intervention might, in theory, be beneficial. Here we worked on the assumption that it is unlikely that the effects of homeopathic care are conveyed by unique mechanisms. In other words, broader psychological and anthropological theories of healing should contribute to our understanding of homeopathy. We explored literature on the placebo effect[9], universal anthropological models [10], psychotherapeutic practices [11] and psychological models such as disclosure theory [12]. We also took expert opinion from practitioners in fields such as gestalt and narrative therapy [13]. We used this knowledge to sensitise us to processes revealed in stage two of the MRC framework, which involves the direct observation and modelling in a real-world context. The purpose of this modelling is to “identify the components of the intervention and underlying mechanims by which they will influence outcome”.

In this paper we present the findings of formal case series approach to the study of 18 patients referred for care at Bristol Homeopathic Hospital (BHH). This is the first time that the process of routine homeopathic care has been the focus of systematic qualitative study. By defining potential active ingredients in this way we hope to shed important light on the concept of “non-specific” effects and provide a more nuanced approach to the workings of homeopathy than can be found in the RCT.

In summary, our objective was to identify and evalute potential “active ingredients” of the homeopathic approach in a prospective formal case series, which draws on actual consultation data, and is based on the MRC framework for the evaluation of complex interventions.

About the author

Trevor DB Thompson

Trevor DB Thompson

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