DL-Phenylalanine is a mixture of both the D and L forms of the amino acid phenylalanine. It is an essential amino acid useful for CNS. DL-Phenylalanine, also known as DLPA, and contains different forms of the essential amino acid Phenylalanine. The "L" form is a natural substance normally found in protein rich foods. The "D" form of this amino acid is made synthetically. DL-Phenylalanine is used to relieve cases of minor depression and other mood issues as well as and physical discomforts and pain. This supplement has also been used for opiate withdrawal symptoms. DLPA is also often combined with other mood boosting supplements and taken in a nootropic stack.