There may be benefits that have not yet been proven through research.
Phenylalanine is an essential amino acid. It is found in high-protein foods. It may improve memory and learning ability. It may enhance mood and alertness. It may help treat some types of depression. It's been used to help treat schizophrenia and Parkinson disease.
Phenylalanine is used in some artificial sweeteners. It tends to decrease appetite. It's been used to treat obesity.
It's also claimed to boost pain tolerance in premenstrual syndrome and migraine headaches.