Promote a positive mood with Natrol 5-HTP. An amino acid, 5-HTP naturally increases serotonin in the body. Serotonin is the chemical messenger that affects emotions, behavior, appetite, thought and sleep. Regular use of Natrol 5-HTP helps promote a more positive outlook and supports relaxation, calm and greater appetite control. No yeast, wheat, corn, milk, egg, soy, gluten, artificial colors or flavors or added sugar, starch of preservatives.