McDermott, C, Richards, S C M, Thomas, P W et al. · QJM : monthly journal of the Association of Physicians · 2006 · DOI
This study tested whether a supplement called BioBran MGN-3 could reduce fatigue in people with ME/CFS by boosting immune cells called natural killer cells. Seventy-one patients took either the supplement or a placebo for 8 weeks. Both groups improved during the study, but the supplement group did not improve significantly more than the placebo group, suggesting the supplement itself was not the reason for improvement.
Natural killer cell dysfunction has been proposed as a mechanism in ME/CFS, making immune-modulating therapies a theoretically attractive approach. This well-designed trial demonstrates that not all biologically plausible treatments work in practice, and highlights the critical role of rigorous controlled studies in preventing ineffective treatments from being promoted to vulnerable patients.
This study does not prove that NK cell dysfunction is irrelevant to ME/CFS pathogenesis—only that this particular supplement does not effectively enhance NK cell function in a clinically meaningful way. It does not establish that all immune-based interventions are ineffective. The improvement in both groups suggests either a placebo response, natural disease fluctuation, or non-specific effects of study participation—but causation cannot be determined.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
McDermott, C, Richards, S C M, Thomas, P W, Montgomery, J, & Lewith, G (2006). A placebo-controlled, double-blind, randomized controlled trial of a natural killer cell stimulant (BioBran MGN-3) in chronic fatigue syndrome.. QJM : monthly journal of the Association of Physicians. https://doi.org/10.1093/qjmed/hcl063
BibTeX
@article{mecfsatlas-mcdermott-2006-placebo-controlled,
author = {McDermott, C and Richards, S C M and Thomas, P W and Montgomery, J and Lewith, G},
title = {A placebo-controlled, double-blind, randomized controlled trial of a natural killer cell stimulant (BioBran MGN-3) in chronic fatigue syndrome.},
journal = {QJM : monthly journal of the Association of Physicians},
year = {2006},
doi = {10.1093/qjmed/hcl063},
note = {PubMed: 16809351},
url = {https://www.mecfsatlas.com/evidence/mcdermott-2006-placebo-controlled},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-25. https://www.mecfsatlas.com/evidence/mcdermott-2006-placebo-controlled
Contribute
Private, reviewed by a human. Not a public comment thread.