Used as a biochemical tool in research to inhibit phenylalanine hydroxylase, an enzyme involved in amino acid metabolism. It helps study metabolic disorders related to phenylalanine, such as phenylketonuria (PKU). Also employed in experiments to induce phenylalanine accumulation in cell cultures and animal models, allowing scientists to investigate oxidative stress and neurotoxicity associated with high phenylalanine levels. Its ability to cross the blood-brain barrier makes it valuable in neuroscience research focusing on amino acid transport and brain metabolism.