L-tryptophan is an essential amino acid that serves as a precursor to serotonin. It is often used in supplements to promote relaxation and improve sleep quality. It can be used as a nutrient in foods.
L-Tryptophan
Found In
- Dairy alternatives
- Dietary supplements
- Infant formulas
- Protein shakes
Also Known As
- L-Triptofano
- L-Trypt
- L-Tryptophane
- L-2-Amino-3-(indole-3-yl) Propionic Acid
- Tryptophan
The Beverage Bottom Line
L-tryptophan is authorized for use in certain foods in the U.S. and Europe. L-tryptophan is not authorized in Canada.
This ingredient may have authorizations in countries not included on this site.
International Assessments and Authorizations
Health Canada
Health Canada has authorized L-tryptophan for use in certain foods. Industry is encouraged to discuss regulatory options for their specific products with Health Canada.
In 2005 and 2006, dietary reference intakes for L-tryptophan were reviewed by the National Academies of Sciences, Engineering and Medicine.
This page was last updated on 6/30/2025.