Overview
Phenylalanine is an Essential Amino Acid, the body needs it for health but cannot make it. Phenylalanine is found in 3 forms: L-phenylalanine, the natural form found in proteins; D-phenylalanine, a mirror image of L-phenylalanine that is made in a laboratory a synthetic form; and DL-phenylalanine, a combination of the 2 forms. Phenylalanine is used in the body to make tyrosine, another amino acid needed to make proteins in b ...