LY255582 is a selective centrally active opioid receptor antagonist with high affinity for mu, delta and kappa receptors with Ki of 0.4 nM, 5.2, 2.0 nM, respectively. LY255582 inhibits diet-associated increases in mesolimbic dopamine levels and reduces consumption of food intake. LY255582 is commonly used in obesity research. LY255582 is a potential compound for the study of opioid receptor-mediated cell signaling.