NutriVouch
Confidence level
Moderate evidence
306 studies

L-Tryptophan

Last reviewed: 4/3/2026

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Absorption
Take on an empty stomach or with a carbohydrate-rich snack (not high-protein) to reduce competition with other amino acids for brain uptake. Vitamin B6 is a cofactor in the conversion to serotonin.
Daily Dose
Common dose: 500 mg-1 g before bedtime for sleep; 0.14-3 g/day for mood
RDA: No supplement RDA; dietary: ~3.5-6 mg/kg/day
Upper limit: No established; up to 3 g/day used in studies
Best form: Free-form L-tryptophan
Timing: 30-45 minutes before bedtime for sleep
Doses >=1 g consistently show reduced sleep latency. Avoid combining with SSRIs or MAOIs (serotonin syndrome risk).
Food Sources
  • Turkey breast~340 mg per 100g
  • Pumpkin seeds~576 mg per 100g
  • Cheddar cheese~320 mg per 100g
  • Oats~230 mg per 100g

Not medical advice