Calcitonin Gene Related Peptide (CGRP) (83-119), rat (TFA) belongs to the calcitonin family of neuropeptides which also includes adrenomedullin, amylin, calcitonin, intermedin and calcitonin receptor-stimulating peptide. Calcitonin Gene Related Peptide (CGRP) has two isoforms (αCGRP and βCGRP), and acts through calcitonin receptor-like receptor (CRLR). Calcitonin Gene Related Peptide (CGRP) plays a key role in migraine pathophysiology and is associated with activation of the trigeminovascular system. CGRP prossibly acts postjunctionally in these areas putatively involved in primary headaches.