Double-blind study of 5-hydroxytryptophan versus placebo in the treatment of primary fibromyalgia syndrome

J Int Med Res. 1990 May-Jun;18(3):201-9. doi: 10.1177/030006059001800304.


A double-blind, placebo-controlled study of the efficacy and tolerability of 5-hydroxytryptophan (5-HTP) was conducted in 50 patients with primary fibromyalgia syndrome. All the clinical parameters studied were significantly improved by treatment with 5-HTP and only mild and transient side-effects were reported. Further controlled studies are required to define properly the value of 5-HTP in patients with primary fibromyalgia syndrome.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • 5-Hydroxytryptophan / therapeutic use*
  • Anxiety
  • Clinical Trials as Topic
  • Double-Blind Method
  • Fatigue
  • Fatigue Syndrome, Chronic / drug therapy*
  • Fatigue Syndrome, Chronic / physiopathology
  • Fatigue Syndrome, Chronic / psychology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pain
  • Placebos
  • Sleep


  • Placebos
  • 5-Hydroxytryptophan