Please use this link to access this publication. Abstract Objectives. To characterize the prevalence and reasons for the use of cannabis as a strategy to reduce the harms arising from other substances. Methods. We drew data about recent cannabis use and intentions from 3 prospective cohort studies of marginalized people who use drugs based in Vancouver, Canada, from June 2016 to May 2018. The primary outcome was “use of cannabis for harm reduction,” defined as using cannabis for substitution for licit or illicit substances such as heroin or other opioids, cocaine, methamphetamine, or alcohol; treating withdrawal; or coming down off other drugs. Results. Approximately 1 in 4...