The present invention relates to novel analogues of neuropeptide Y, pharmaceutical compositions containing the same, pharmaceutical formulations containing the same, and method of treating diseases or conditions mediated by neuropeptide Y-receptor binding. More particularly, the present invention relates to novel analogues of neuropeptide Y having at least one unnatural amino acid substitution, such as 4Hyp at position 34 , that selectively bind to the neuropeptide Y1 receptor subtype compared to the neuropeptide Y2 receptor subtype.