Monoclonal antibodies targeting calcitonin gene-related peptide (mAb-CGRP) have shown efficacy and effectiveness in the treatment of episodic and chronic migraine, however, not all patients respond to them. Preliminary data suggests that some patients who failed to one of them, may respond to a different anti-CGRP monoclonal antibody. Observational analytic study with a retrospective cohort design including patients treated with a second mAb-CGRP due to lack of response to the first one. The aim of this study is to provide Class II evidence about the effectiveness and tolerability of the mAb-CGRP switching in patients with migraine, treated in a real-world setting.