NOW L-Tryptophan 500 mg provides an essential amino acid that the body must obtain from food or supplements because it cannot produce it on its own. L-Tryptophan plays a role in the body’s natural production of serotonin and melatonin, compounds involved in mood balance and normal sleep cycles. This supplement is commonly used to support relaxation and overall wellness as part of a balanced lifestyle. NOW Foods tests every lot for quality and purity, including screening for Peak E and microbial contamination, to help ensure a reliable product. Each capsule delivers 500 mg of L-Tryptophan in a convenient daily supplement format.