A pharmaceutical composition with a peptide analog of apelin, and a method of treatment for various conditions are described. An exemplary embodiment is a peptide analog comprising at least residues 2-13 of SEQ ID NO: 1 and further comprising at least a substitution or modification at residue 13 of SEQ ID NO: 1. A pharmaceutical composition comprising the peptide analog of the present invention and method of treatment for diabetes, stimulating insulin release, and moderating blood glucose excursions by administering the peptide analog of the present invention to a patient in need thereof are described.
