Provided herein are peptide combinations comprising a GIP agonist peptide and a glucagon antagonist peptide. In some embodiments, the peptide combination is provided as a composition, e.g., a pharmaceutical composition, while in other embodiments, the peptide combination is provided as a kit. In yet other embodiments, the peptide combination is provided as a conjugate, e.g., a fusion peptide, a heterodimer. In specific aspects, the GIP agonist peptide is an analog of native human glucagon. In specific aspects, the glucagon antagonist peptide is an analog of native human glucagon. In some embodiments, the GIP agonist peptide is covalently attached to the glucagon antagonist peptide via a linker. Methods of treating a disease, e.g., a metabolic disorder, such as diabetes and obesity, comprising administering the peptide compositions described herein are further provided.
