L-tryptophan
Essential amino acid from protein-rich food, precursor of serotonin and melatonin.
What the research shows
Shown, with a clear condition or a limited scope.
Sutanto (2022) could pool only 4 articles: only time awake after falling asleep improved, the other sleep measures did not. Kikuchi (2021) reviewed 11 trials on mood in healthy adults, which is separate from sleep and from depression as a condition. There is little material to build on.
Who it makes sense for: People who often lie awake at night and are willing to take at least one gram a day.
How we weigh evidenceClinical dosage
Scientific sources
The clinical dosages on this page are based on peer-reviewed research.
We keep the dosages and values on this page as accurate as possible based on selected studies. New research may change these values. Nothing on this page is medical advice. If you have any doubts, always consult a doctor.