Intraperitoneal (i.p.) injection of naltrexone (NAL) or melanotan-II (MTII) blunt binge-like ethanol drinking (A & C) and associated blood ethanol concentrations (B & D) in C57BL/6J mice when administered over a range of concentrations (0, 0.3, 1.0, 3.0, & 10.0 mg/kg). Ethanol consumption is expressed as mean intake (± SEM) over the 2-h test in g/kg, and BECs are expressed as mean (± SEM) mg/dl of ethanol in blood. Data were analyzed with one-way ANOVAs and post hoc Tukey’s test. * P < 0.05 (two tailed).