From the Manufacturer:
DL-Phenylalanine produces and maintains an elevated and positive mood, alertness and ambition. It enhances learning and memory, produces neurotransmitters which control impulse transmission between nerve cells, and is involved in dopamine transmission. Also used in the treatment of certain types of depression and to suppress appetite. Each capsule provides 500 mg DL-phenylalanine as a 50/50 (equimolar) mixture of D-Phenylalanine and L-Phenylalanine.