A 50/50 blend of the D- and L- form of the amino acid phenylalanineA precursor to two neurotransmitters that help support an alert state375 mg per tabletSource Naturals DLPA DL-Phenylalanine is an equal blend of the D- and L- forms of the amino acid phenylalanine. Some researchers believe that D-phenylalanine (DPA) inhibits the action of an enzyme that breaks down endorphins and enkephalins, which are proteins that bind to opioid receptor sites in the brain. DPA may extend the life of endorphins and enkephalins, which are known for their positive influence on comfort levels.These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.