MAC-545496 is primarily used as a selective and potent antagonist of the orexin OX1 receptor. Its main application lies in neuroscience research, particularly in studies related to sleep-wake regulation, addiction, and anxiety-related behaviors. By selectively blocking OX1, it helps differentiate the roles of orexin receptor subtypes, making it a valuable tool in understanding the orexin system's involvement in arousal and reward pathways. It has been utilized in preclinical models to investigate potential treatments for substance use disorders, especially in reducing drug-seeking behavior. Additionally, MAC-545497 (a close analog) and related compounds support research into insomnia and other central nervous system disorders, though MAC-545496 itself remains a research compound with no clinical use to date.