Cannabis Substitution in Managed Alcohol Programs Reduces Daily Drinking, Study Finds

(Photo credit: turk_stock_photographer).

The study was conducted by researchers at the University of Victoria, who evaluated a pilot program launched in January 2023 that allowed participants to choose a pre-rolled marijuana joint instead of one of their scheduled alcohol doses. The review covers 35 participants and draws on multiple data sources, including two years of program records, five rounds of surveys, and in-depth interviews. Researchers tracked how often participants used cannabis, how much alcohol they consumed over time, and how individual patterns shifted across the study period.

According to the findings, individuals who used more cannabis on average tended to drink less overall. The researchers calculated that each 0.4-gram joint—roughly equivalent to 15 THC units—was linked to a reduction of about 2.4 standard drinks per day. However, changes in cannabis use from day to day did not correspond with immediate shifts in drinking, suggesting the substitution effect reflects broader trends rather than moment-to-moment decisions.

The study also reports that alcohol use declined over the course of the program, with interviews shedding light on how participants made decisions about substance use in a structured harm-reduction environment. Researchers say the results support exploring cannabis as a tool within Managed Alcohol Programs to reduce alcohol-related harms and improve long-term outcomes.

“This study highlights the potential for cannabis substitution to meaningfully reduce alcohol-related harms”, concludes the study. “Implications for program development and future research evaluating changes in health, wellbeing, and harm outcomes are discussed.”