Used as a metabolic marker in clinical diagnostics, particularly for the assessment of catecholamine metabolism. It is relevant in the evaluation of neuroendocrine tumors such as pheochromocytoma and neuroblastoma, where levels in urine can indicate abnormal metabolic activity. Also employed in research settings to study oxidative metabolism and enzyme function related to aromatic compounds. Its stability as a monohydrate makes it suitable for use in standardized diagnostic kits and laboratory reference materials.