Cannabis Substitution Reduces Alcohol Use in Managed Alcohol Program | Research

The takeaway

In a Canadian managed alcohol program, each additional cannabis joint consumed was associated with about 2.4 fewer standard drinks per day, providing real-world evidence that cannabis can substitute for alcohol in harm reduction settings.

Harm reduction practitioners, addiction medicine professionals, policy makers evaluating cannabis substitution, and researchers studying alcohol use disorder interventions.

What the researchers found

A significant between-person substitution effect was found: participants who used more cannabis on average also consumed less alcohol, with each additional 0.4g joint (approximately 76 mg THC) associated with 2.43 fewer mean daily standard drinks.

Why it matters

This is one of the first studies to evaluate cannabis substitution within a structured harm reduction program, showing that offering cannabis as an alternative to alcohol can meaningfully reduce drinking in people with severe alcohol use disorder.

The numbers in context

N=35 participants; 5 survey waves over 13 months; each additional 0.4g joint (~76 mg THC, ~15.2 standard THC units) associated with 2.43 fewer daily standard drinks; alcohol use also declined over time; 14 qualitative interviews

How the study worked

Mixed-methods longitudinal study within a Canadian managed alcohol program (N=35) using five waves of quantitative surveys (Jan 2023-Feb 2024), two years of program records, hierarchical mixed-effects models, and 14 qualitative interviews.

What this study cannot tell us

Small sample (N=35); single program site; no control group; observational substitution effect (not randomized); between-person effect only (within-person fluctuations not significant); self-selected participants; limited generalizability.

How to read the evidence

Longitudinal mixed-methods design within a real-world program provides practical evidence, but small sample, single site, and lack of randomization limit causal inference.

When this study was published

Published 2026; data from January 2022 to February 2024.

The bigger picture

With alcohol causing more health damage than cannabis in most metrics, cannabis substitution programs represent a pragmatic harm reduction strategy that could save lives among those with severe alcohol use disorder.

Questions still open

Would this work in larger, multi-site studies? Does cannabis substitution improve health outcomes beyond reduced drinking? What are the optimal dosing strategies? Could this model be adopted in other countries?

Common questions

Can cannabis help people drink less alcohol?

This Canadian study found a significant substitution effect in a managed alcohol program — participants who used more cannabis consumed less alcohol, with each joint associated with about 2.4 fewer standard drinks per day.

What is a managed alcohol program?

MAPs provide measured doses of beverage alcohol alongside housing and social support to stabilize drinking in people with severe alcohol use disorder and housing instability, reducing emergency visits and alcohol-related harms.

Read the original research

Evaluating cannabis substitution for alcohol within the context of a canadian managed alcohol program.

The International journal on drug policy, 147, 105083

View on PubMed ↗Publisher’s paper ↗

Citation

Goulet-Stock, Sybil; Hacksel, Catherine; Scandiuzzi, Beatriz; Boyd, Rob; Pauly, Bernie; Stockwell, Tim. (2026). Evaluating cannabis substitution for alcohol within the context of a canadian managed alcohol program.. The International journal on drug policy, 147, 105083. https://doi.org/10.1016/j.drugpo.2025.105083