Canada is in the midst of an opioid epidemic. Although oral opioid agonist therapies (OAT) are effective for the treatment of opioid use disorder (OUD), a number of barriers pose a significant challenge to treatment initiation and retention. In 2018, Health Canada approved a new medication for OUD, a once-monthly injection, which may be able to address challenges related to medication adherence. The current project aims to support a larger observational study that assess the feasibility, efficacy, and safety of this new treatment option.