Now Foods, 5-HTP, Double Strength, 200 mg, 120 Veg CapsulesNeurotransmitter Support Supports Positive Mood With Glycine, Taurine & Inositol Non GMO A Dietary Supplement Vegetarian Vegan Kosher Amino Acids Family Owned Since 1968 GMP Quality Assured 5 HTP, the intermediate metabolite between the amino acid L tryptophan and serotonin, is extracted from the seed of an African plant (Griffonia simplicifolia). Now Double Strength 5 HTP has twice the 5 HTP (200 mg per capsule) as in our regular strength product