l-5-Hydroxytryptophan is the precursor to serotonin, a mood and appetite regulating neurotransmitter produced within the body. It has been combined with Vitamin C and Vitamin B6, an important cofactor in the conversion to serotonin. Nature's Way uses natural l-5-HTP extracted from Griffonia simplicifolia beans produced in easy-to-swallow, enteric-coated tablets to minimalize any potential gastric discomfort.