Cannabis Substitution Reduces Alcohol Use in Managed Alcohol Program

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.

Goulet-Stock, Sybil et al.·The International journal on drug policy·2026·Moderate Evidencelongitudinal
RTHC-08292LongitudinalModerate Evidence2026RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
longitudinal
Evidence
Moderate Evidence
Sample
N=35

What This Study 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.

Key Numbers

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 They Did This

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.

Why This Research 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 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.

What This Study Doesn't 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.

Questions This Raises

  • ?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?

Trust & Context

Key Stat:
Evidence Grade:
Longitudinal mixed-methods design within a real-world program provides practical evidence, but small sample, single site, and lack of randomization limit causal inference.
Study Age:
Published 2026; data from January 2022 to February 2024.
Original Title:
Evaluating cannabis substitution for alcohol within the context of a canadian managed alcohol program.
Published In:
The International journal on drug policy, 147, 105083 (2026)
Database ID:
RTHC-08292

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked 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 More on RethinkTHC

Cite This Study

RTHC-08292·https://rethinkthc.com/research/RTHC-08292

APA

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

MLA

Goulet-Stock, Sybil, et al. "Evaluating cannabis substitution for alcohol within the context of a canadian managed alcohol program.." The International journal on drug policy, 2026. https://doi.org/10.1016/j.drugpo.2025.105083

RethinkTHC

RethinkTHC Research Database. "Evaluating cannabis substitution for alcohol within the cont..." RTHC-08292. Retrieved from https://rethinkthc.com/research/goulet-stock-2026-evaluating-cannabis-substitution-for

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.