L-tryptophan is an essential amino acid and hence cannot be synthesized by the body; but must be obtained from food or supplements. Because L-tryptophan is converted to serotonin (5-hydroxytryptamine) and melatonin in the body; it plays an important role in promoting relaxation; restful sleep and positive mood.* L-tryptophan may also help in reducing carbohydrate cravings.* Jarrow FORMULAS L-Tryptophan TryptoPure is manufactured at a GMP facility via fermentation from vegetable materials. Suitable for vegetarians/vegans. Keep out of the reach of children.