Used in the treatment of phenylketonuria (PKU), a genetic disorder where the body cannot metabolize phenylalanine properly. It helps in reducing phenylalanine levels in the blood by enhancing the activity of phenylalanine hydroxylase, an enzyme crucial for phenylalanine metabolism. Also employed in research studies to understand neurotransmitter synthesis and function, particularly in the context of dopamine and serotonin production. Additionally, it has potential applications in managing certain neurological disorders due to its role in nitric oxide synthase activity, which is important for vascular and neurological health.