Used primarily in medical research to study the effects of neurotransmitters and their pathways in the brain. It serves as a metabolite of L-DOPA, helping researchers understand the metabolism and pharmacokinetics of Parkinson's disease treatments. Additionally, it is utilized in biochemical studies to explore the role of catecholamines in neurological disorders. Its application extends to investigating the blood-brain barrier's permeability and the development of therapeutic agents targeting central nervous system diseases.