The neuropeptide FF (NPFF) system, first identified in bovine brain extract in 19859,10, has been found to be involved in a variety of physiological processes, including food intake, blood pressure regulation, memory, insulin release, neural regeneration, metabolic disease, and cardiovascular activity11–16, via activation of a Gi/o protein-coupled receptor located in the nervous system17,18. Here, NPFF is linked to metabolic disease.