CP-945598 HCl is primarily used in research settings to study the endocannabinoid system, particularly its role in appetite regulation and obesity. It acts as a selective antagonist for the CB1 receptor, helping scientists understand the mechanisms behind hunger, metabolism, and energy balance. This compound has been instrumental in preclinical studies exploring potential therapeutic interventions for metabolic disorders and weight management. Additionally, it aids in investigating the broader physiological and psychological effects of cannabinoid receptor modulation, including its implications in addiction and neurological conditions.