For Relaxation, Positive Mood & Sleep Vegan Veggie Caps Dietary Supplement TryptoPure Suitable for Vegetarians/Vegans 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.