NOW L-Tryptophan

• Source of an essential amino acid for the maintenance of good health

L-Tryptophan is a large neutral amino acid essential to human metabolism because it is the metabolic precursor of serotonin (a neurotransmitter), melatonin (a neurohormone), and niacin (vitamin B3) which assist in the regulation of sleep, positive mood and immune function. L-Tryptophan is not synthesized by the body and must be obtained from the diet.