Provided herein are neuropeptide-2 receptor agonists of the formula (I): Y—R1—R2—X—R3—R4—R5—R6—R7—R8—R9—R10—R11—R12—R13—R14—NH2  (I) (SEQ ID NO: 1), as well as pharmaceutically acceptable salts, derivatives and fragments thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of diseases such as, for example, obesity and diabetes.