Galcanezumab (Emgality®) is a humanized monoclonal antibody targeting the calcitonin gene-related peptide (CGRP), thereby inhibiting its physiological activity, with CGRP playing a key role in the pathophysiology of migraine and headache disorders. In pivotal phase 3 trials, recommended dosages of subcutaneous galcanezumab once monthly were significantly more effective than placebo as preventive therapy in adults with episodic (EVOLVE-1 and -2; over 6 months) or chronic (REGAIN; over 3 months) migraine (± aura), including in patients who had failed several prior preventive migraine drugs (CONQUER; over 3 months). The beneficial effects of galcanezumab preventive treatment in reducing the number of monthly migraine headache days (MHDs) and improving health-related quality of life (HR-QOL) were sustained during up to 1 year of treatment. In adults with episodic cluster headache, galcanezumab treatment was associated with a significant reduction in the weekly frequency of cluster headache attacks across weeks 1-3 compared with placebo (primary endpoint), albeit during weeks 4-8, there was a convergence of results between these treatment groups. Although further evidence from the clinical setting is required to determine its long-term safety profile, given its convenient administration regimen, efficacy and short-term tolerability profile, monthly galcanezumab represents an important emerging option for the prevention of episodic and chronic migraine (± aura) and the treatment of episodic cluster headache.