The embodiments provide a modified calcitonin gene related peptide antagonist including an N terminal fragment of modified calcitonin gene related peptide or related protein family member where at least two residues of the N terminal fragment are cysteine (Cys) and at least one amino acid comprises a non threonine substitution of a threonine (Thr) residue a central core where the central core comprises an oc helix and a C terminal fragment of modified calcitonin gene related peptide or related protein family member comprising a C terminal amide and where at least one amino acid of the C terminal fragment is phenylalanine (Phe) proline (Pro) tyrosine (Tyr) or hydroxyproline (Hyp) or pharmaceutically acceptable salt thereof as well as compositions including pharmaceutical compositions comprising a subject peptide. The embodiments further provide treatment methods including methods of treating a migraine the methods generally involving administering to an individual in need thereof an effective amount of a subject peptide or composition.
