Neurotransmitter Support Supports a Positive Mood Non-GMO A Dietary Supplement Vegetarian/Vegan Amino Acids Family Owned Since 1968 GMP Quality Assured 5-HTP is a naturally occurring amino acid that's a precursor for the neurotransmitter serotonin, which supports a positive mood and outlook and may help to manage appetite. NOW 5-HTP Sustained Release (Amino SR) Tablets allow for steady release and more gradual utilization of 5-HTP, and may be better tolerated by individuals who are sensitive to conventional 5-HTP supplements. This product is designed to release over an extended period of time.