DL-PhenylalaninePure Encapsulations DL Phenylalanine is an amino acid supplement that provides both the D and L forms of phenylalanine in convenient capsule form. This essential amino acid serves as a precursor to important neurotransmitters and endorphins. Each capsule contains DL Phenylalanine, providing both forms of this amino acid to support the body's natural production of neurotransmitters like dopamine and norepinephrine. The combination of D and L forms