NPY1R (Neuropeptide Y receptor type 1) is a receptor for neuropeptide Y that is the most abundant peptide present in the mammalian central and peripheral nervous system. Neuropeptide Y exhibits a variety of potent central and peripheral effects including those on feeding, memory, blood pressure, cardiac contractility and intestinal secretions. Neuropeptide Y effects are mediated by several different receptor subtypes, Y-1, Y-1-like, Y-2, Y-3, Y-4 and Y-5. NPY1R is correlated with food feeding and subnanomolar antagonists of NPY1R have been discovered as potential anti-obesity agents. NPY1R is also involved in cardiovascular actions of exogenous neuropeptide Y and plays a role in maintaining basal blood pressure and heart rate in ischaemic heart failure.