Phenylalanine is actually one of the basic amines that make up proteins. There’s no issue with it inherently unless you have a genetic disorder, Phenylketonuria, that keeps you from being able to turn it into tyrosine. read more
Phenylalanine occurs naturally in many protein-rich foods, such as milk, eggs and meat. Phenylalanine also is sold as a dietary supplement. The artificial sweetener aspartame (Equal, NutraSweet), which is added to many medications, diet foods and diet sodas, contains phenylalanine. read more