CGRP antagonists block the calcitonin gene-related peptide receptor, inhibiting the vasodilatory and pro-inflammatory effects of CGRP in cluster headache pathogenesis. By preventing CGRP binding, these medications reduce neurogenic inflammation and vascular dilation, thereby interrupting the cascade of events that trigger severe headache symptoms. The result is a significant reduction in headache frequency, intensity, and duration for cluster headache patients.