Phenylalanine is used for depression, attention deficit-hyperactivity disorder (ADHD), Parkinson's disease, chronic pain, osteoarthritis, rheumatoid arthritis, alcohol withdrawal symptoms, and a skin disease called vitiligo.

Some people apply it directly to the skin for vitiligo

Phenylalanine is an amino acid, a "building block" of protein. L-phenylalanine is an essential amino acid and is the only form of phenylalanine found in proteins.

The amount of this amino acid found in foods should not pose a risk for otherwise healthy individuals.

This medicine can be consumed by pregnant and breastfeeding women unless absolutely necessary in a certain quantity.

 Phenylalanine should be avoided in people with certain inherited disorders that cause their bodies to build up too much phenylalanine.

People with this disorder can develop mental retardation, high blood pressure, stroke, and many other serious health issues if they consume phenylalanine.