Galanin-like peptide (GALP) is a neuropeptide involved in the regulation of food intake behavior, body weight and energy metabolism. In previous studies, we demonstrated that the intranasal administration of GALP has weight loss effects, although the mechanism of this action was not clarified. The aim of this study was to demonstrate the functional significance of GALP on lipid metabolism in the liver. Mice were fed a high fat diet to cause diet-induced obesity (DIO) and then administered GALP intranasally for 2 weeks (experimental), or vehicle (control). Body weights, along with lipid levels in the plasma and liver, and lipid metabolism-related gene expression in the liver were subsequently measured. Body weight gain was decreased by the GALP treatment compared to the control group. Lipid droplet levels in hepatocytes and hepatic triglyceride levels were decreased in the GALP group compared with the vehicle group, whereas hepatic fatty acid β-oxidation-related gene mRNA levels were increased in the GALP group. These results suggest that the intranasal administration of GALP has an inhibitory effect on lipid accumulation in the liver.