5-HTP is a precursor to serotonin, a neurotransmitter involved in sending messages through the nervous system. No Artificial Color, Flavor or Sweetener, No Preservatives, No Sugar, No Starch, No Milk, No Lactose, No Soy, No Gluten, No Wheat, No Yeast , No Fish, Sodium Free. ** These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.