Used as a metabolite marker in biochemical research to study serotonin metabolism. Commonly measured in neurochemical assays to assess serotonin turnover in the brain and peripheral tissues. Applied in studies related to mood disorders, neurodegenerative diseases, and psychiatric conditions. Also utilized in plant physiology research due to structural similarity to auxins, helping in understanding growth regulation mechanisms in plants. Frequently detected in urine, cerebrospinal fluid, and tissue extracts using HPLC and mass spectrometry methods.