Dietary Supplement. DL-Phenylalanine. Free Form Amino Acid. DLPA (DL-Phenylalanine) is an amino acid. TwinLab DLPA is a 50/50 (equimolar) mixture of D-Phenylalanine and L-Phenylalanine. TwinLab DLPA Capsules are easier to swallow and assimilate. Well tole