We identified widespread variation in domperidone utilisation patterns, with domperidone broadly perceived to be effective in increasing breast milk supply. Side effects associated with domperidone treatment were common, appeared to be dose-related, and were frequently associated with treatment cessation. These findings highlight the importance of improved clinical practice recommendations and generation of evidence from additional high-quality clinical trials evaluating the efficacy and safety of domperidone. More conclusive clinical trials are needed to determine the efficacy, as well as optimal dose and duration, of domperidone use.