L-tryptophan and 5-hydroxytryptophan in the treatment of depression. A review

Acta Psychiatr Scand. 1978 Mar;57(3):239-52. doi: 10.1111/j.1600-0447.1978.tb06890.x.


Trials performed do not provide evidence for an antidepressant effect of 5-HTP. L-TP, without interacting pharmaca, does not appear to be a well-documented antidepressant. The only convincing evidence for L-TP as an antidepressant is that L-TP enhances the effect of MAOI.

Publication types

  • Clinical Trial

MeSH terms

  • 5-Hydroxytryptophan / therapeutic use*
  • Antidepressive Agents / therapeutic use
  • Clinical Trials as Topic
  • Depression / drug therapy*
  • Drug Evaluation
  • Humans
  • Placebos
  • Tryptophan / therapeutic use*


  • Antidepressive Agents
  • Placebos
  • Tryptophan
  • 5-Hydroxytryptophan