Phenylalanine is an essential amino acid.
A dietary source of phenylalanine is required, since the body cannot make this amino acid.
Combining phenylalanine with aspartic acid forms aspartame, a synthetic sweetener added to diet drinks and food.
Brain Function: Phenylalanine might improve learning, treat hyperactivity, and act as an antidepressant. This amino acid also might aid in the treatment of Parkinson's disease.