Why French Cannabis Users Grow Their Own Despite Prohibition | Research

The takeaway

Among daily cannabis users in France, 11-16% grew cannabis at home primarily to control product quality, with growers more likely to be older, male, in stable housing, and using cannabis for therapeutic reasons.

Drug policy researchers, harm reduction advocates, anyone interested in cannabis supply patterns under prohibition

Quality management was the top motivation for home cultivation

What the researchers found

Home cultivation was the main supply source for 11-16% of daily French cannabis users. Cultivators were more likely to be older, male, in stable housing, using herbal cannabis, smoking with less tobacco, and using cannabis therapeutically. Most were self-sufficient and few sold any of their crop. The primary motivation was managing product quality.

Why it matters

Home cultivation in prohibition countries represents a harm reduction strategy by users seeking to control what they consume. Understanding who cultivates and why can inform more nuanced drug policy.

The numbers in context

11% and 16% reported home cultivation as main supply in the two samples (N=3,840 and N=574). Quality management was the top motivation. Few sold their crop. Most were self-sufficient. Urban residence and at-risk alcohol use were negatively associated with cultivation.

How the study worked

Analysis of two convenience samples of daily cannabis users in France from online cross-sectional surveys. Multivariable logistic regression identified factors associated with home cultivation. A second analysis described motivations and cultivation patterns.

What this study cannot tell us

Convenience samples of daily users may not represent all cannabis users. Online surveys may miss populations without internet access. Self-reported data in an illegal context may be subject to social desirability bias.

How to read the evidence

Moderate: two independent samples with multivariable analysis, but convenience sampling and self-reported data in a prohibition context

When this study was published

Published in 2025

The bigger picture

Home cultivation under prohibition can be understood as a consumer response to an unregulated market. Growers want to know what they are consuming, which is the same consumer protection that regulated markets aim to provide.

Questions still open

Would home cultivation decrease if France legalized and regulated cannabis? Do home growers actually achieve the quality control they seek? How does home-grown cannabis compare to black market products?

Common questions

Why do people grow cannabis at home in France?

The primary motivation was to manage product quality. In an illegal market, users cannot verify what they are buying. Growing at home gives control over the product. Other reasons included self-sufficiency and therapeutic use.

Are home growers selling their cannabis?

Few reported selling any of their crop. Most were self-sufficient, growing only for personal use. The profile of a typical grower was an older male in stable housing using cannabis for therapeutic reasons.

Read the original research

Home Cultivation of Cannabis in a Context of Prohibition: Results from Two Online Cross-Sectional Surveys of People Using Cannabis Daily in France.

International journal of environmental research and public health, 22(8)

View on PubMed ↗Publisher’s paper ↗

Citation

Bastien, Martin; Mezaache, Salim; Donadille, Cécile; Madrid, Laélia Briand; Lebrun, Maëla; Martin, Victor; Roux, Perrine. (2025). Home Cultivation of Cannabis in a Context of Prohibition: Results from Two Online Cross-Sectional Surveys of People Using Cannabis Daily in France.. International journal of environmental research and public health, 22(8). https://doi.org/10.3390/ijerph22081167