Gluten Free.
L-Tryptophan also supports immune functions because it is the body's precursor to the kynurenines that regulate immunity. The essential amino acid L-Tryptophan helps support relaxation, restful sleep, and feeling better. Source Naturals L-Tryptophan is extremely pure and is regularly tested to ensure the highest standards of quality. If needed, L-Tryptophan converts to niacin in the body, which supports circulation, a healthy nervous system, the metabolism of food, and the production of hydrochloric acid for the digestive system.