Used as a metabolite biomarker in clinical diagnostics, particularly in the assessment of pheochromocytoma and other neuroendocrine tumors. It is a major breakdown product of catecholamines like epinephrine and norepinephrine, making it valuable in urine and plasma tests to evaluate catecholamine metabolism. Elevated levels are indicative of increased catecholamine production, aiding in the diagnosis and monitoring of related disorders. Also utilized in research settings to study metabolic pathways involving monoamine neurotransmitters.