ABD459 is a CB1 receptor antagonist with significant effects on regulating food intake and sleep-wake cycles. ABD459 completely displaces CB1 agonist CP99540 ( K i = 8.6 nM) and antagonizes CP55940-induced GTPγS binding ( K B = 7.7 nM). ABD459 may specifically modulate endogenous cannabinoid release through cholinergic activity and plays a role in attention and arousal regulation. ABD459 is suitable for research in neurological disorders.