Spirulina did not ameliorate idiopathic chronic fatigue in four N-of-1 randomized controlled trials

Phytother Res. 2007 Jun;21(6):570-3. doi: 10.1002/ptr.2114.


Idiopathic chronic fatigue is an exclusion diagnosis established when no chronic disease is found. Spirulina platensis is an alga with a rich content of proteins, vitamins, minerals and amino acids and is considered as a bioactive additive with multiple effects, among them being effects against fatigue. However, despite the worldwide utilization of Spirulina, there are only a few quality studies with it and none concerning fatigue. The N-of-1 randomized trials are made on one patient, and by this kind of study the efficacy of a treatment on that particular patient can be assessed. A series of four N-of-1 double-blind, randomized trials were performed on four physicians who complained of chronic fatigue. Each patient was his own control and received three pairs of treatments comprising 4 weeks of spirulina and 4 weeks of placebo. Spirulina platensis was administered in a dose of 3 g/day. For each pair, the order of treatments was randomized. Outcome measures were severity of fatigue measured on a 10-point scale. The scores of fatigue were not significantly different between spirulina and placebo. Spirulina administered in a dose of 3 g/day did not ameliorate fatigue more than the placebo in any of the four subjects, and possibly it has no effect on chronic fatigue.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Biological Factors / chemistry
  • Biological Factors / therapeutic use
  • Chronic Disease
  • Double-Blind Method
  • Fatigue / drug therapy*
  • Fatigue / pathology
  • Humans
  • Spirulina / chemistry*
  • Treatment Outcome


  • Biological Factors