Central cannabinoid (CB) receptor antagonists and inverse agonists exhibit therapeutic potential for obesity and drug dependence, while being devoid of psychotropic effects. CAY10508 is a potent and selective central cannabinoid (CB) receptor inverse agonist with a K value of 243 nM and an EC of 195 nM. A 10 µM concentration of CAY10508 resulted in 100% and 35% displacement of [H]-CP-55,940 at the CB and peripheral cannabinoid (CB) receptors, respectively. A [35S]-GTPγS binding assay revealed the inverse agonist properties of CAY10508 at the CB receptor.