Luzindole is primarily used in scientific research as a melatonin receptor antagonist. It selectively blocks MT1 and MT2 receptors, making it a valuable tool for studying the role of melatonin in biological processes such as circadian rhythm regulation, sleep-wake cycles, and seasonal reproductive behavior. Researchers use luzindole to investigate how melatonin signaling affects neuroendocrine functions, sleep disorders, and mood-related conditions. Due to its ability to inhibit melatonin’s effects, it helps in understanding the mechanisms of the body's internal clock and potential disruptions in shift work or jet lag. It is not used clinically but remains important in preclinical studies exploring sleep and neurological pathways.