According to the label, most of these reactions were not serious and occurred within hours after receiving the drug, but some occurred more than one week after administration. Because these reactions are voluntarily reported, it is not possible to determine the actual incidence or establish causality. Hypersensitivity reactions, including rash, urticaria, and dyspnea, were reported during pre-approval clinical trials of fremanezumab-vfrm (Ajovy) and galcanezumab-gnlm (Emgality), the other FDA-approved CGRP blockers.2 Because of the long half-lives of these drugs, hypersensitivity reactions may be prolonged.