A placebo-controlled, double-blind, randomized controlled trial of a natural killer cell stimulant (BioBran MGN-3) in chronic fatigue syndrome

QJM. 2006 Jul;99(7):461-8. doi: 10.1093/qjmed/hcl063. Epub 2006 Jun 29.


Background: Previous research has suggested that natural killer (NK) cell activity may be reduced in patients with chronic fatigue syndrome (CFS).

Aim: To evaluate the effectiveness of a putative NK cell stimulant, BioBran MGN-3, in reducing fatigue in CFS patients.

Design: Randomized, double-blind, placebo-controlled trial.

Methods: We recruited 71 patients with CFS (according to the Centers for Disease Control 1994 criteria) attending an out-patient specialist CFS service. Participants were given oral BioBran MGN-3 for 8 weeks (2 g three times per day) or placebo equivalent. The primary outcome measure was the Chalder physical fatigue score. Self-reported fatigue measures, self-assessment of improvement, change in key symptoms, quality of life, anxiety and depression measures were also included.

Results: Data were complete in 64/71 patients. Both groups showed marked improvement over the study duration, but without significant differences. Mean improvement in the Chalder fatigue score (physical scale) was 0.3 (95%CI -2.6 to 3.2) lower in the BioBran group.

Discussion: The findings do not support a specific therapeutic effect for BioBran in CFS. The improvement showed by both groups over time highlights the importance of placebo controls when evaluating interventions in CFS.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Double-Blind Method
  • England
  • Fatigue Syndrome, Chronic / complications
  • Fatigue Syndrome, Chronic / drug therapy*
  • Female
  • Humans
  • Killer Cells, Natural / drug effects*
  • Male
  • Mental Disorders / complications
  • Polysaccharides / therapeutic use*
  • Quality of Life
  • Self Disclosure
  • Treatment Outcome
  • Xylans / therapeutic use*


  • Polysaccharides
  • Xylans
  • polysaccharide MGN3