Neurotransmitter Support Supports Positive Mood With Glycine, Taurine & Inositol Non-GMO A Dietary Supplement Vegetarian/Vegan Kosher Amino Acids Family Owned Since 1968 GMP Quality Assured5-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 (100 mg per capsule).