AbstractBackgroundGalcanezumab is a monoclonal antibody acting against the calcitonin gene‐related peptide approved for the preventive treatment of migraine. The aim of this article is to explore its effectiveness and safety of galcanezumab in chronic migraine (CM) with medication overuse‐headache (MOH).MethodsSeventy‐eight patients were consecutively enrolled at the Modena headache center and followed up for 15 months. Visits were scheduled every 3 months, and the following variables were collected: the number of migraine days per month (MDM); the painkillers taken per month (PM); the number of days per month in which the patient took, at least, one painkiller; the six‐item headache impact test; and the migraine disability assessment questionnaire (MIDAS) score. Demographic features of the analyzed sample were collected at the baseline and adverse events (AEs) were collected at every visit.ResultsAfter 12 months, galcanezumab significantly reduced the MDM, the PM, the number of days on medication, the HIT‐6 as well as the MIDAS scores (allp< .0001). The greatest amelioration was obtained in the first trimester of treatment. A higher MDM, a higher NRS score at the baseline, and a higher number of failed preventive treatments negatively predict the CM relief at the year of treatment. No serious AEs were registered and only one drop‐out was due to AE.ConclusionsGalcanezumab is effective and safe for the treatment of patients affected by CM and MOH. Patients with a higher impairment at the baseline may found less benefits with galcanezumab.