A blood sugar-modulating polypeptide, a pharmaceutical composition comprising the polypeptide, and a method for modulating blood sugar in a mammal comprising the administration of the polypeptide are provided. The polypeptide has a following amino acid sequence or a homologous amino acid sequence derived from the substitution, deletion, and/or addition of one or more amino acids therein:RVRVWVTERGIVARPPTIG (SEQ ID NO. 11).
