SB408124 is a selective non-peptide antagonist of the orexin-2 (OX₂) receptor (pK_i = 7.9), with much lower affinity for the orexin-1 (OX₁) receptor. It is primarily used in research to investigate the orexin system's role in regulating sleep-wake cycles, arousal, feeding behavior, and stress responses. This compound serves as a valuable tool in pharmacological studies exploring potential therapies for disorders such as narcolepsy, insomnia, obesity, and addiction. Applications include in vitro receptor binding assays, functional studies on G-protein coupled receptor signaling, and in vivo models assessing effects on locomotor activity, sleep architecture, and metabolic processes.