Used primarily in research settings to study melatonin receptors and their functions. It serves as a radioligand in binding assays, helping to understand the mechanisms of melatonin in regulating sleep, circadian rhythms, and other physiological processes. Its iodinated structure allows for easy detection in experimental studies, making it valuable for investigating receptor distribution and affinity in various tissues. Additionally, it aids in the development of therapeutic agents targeting melatonin-related disorders.