Cannabis Co-Users Were Less Likely to Switch Away from Cigarettes | Research

The takeaway

In a study of 160 cigarette smokers, those who also used cannabis smoked significantly more regular cigarettes during weeks when asked to switch to alternative products and were less likely to attempt quitting tobacco.

Tobacco cessation clinicians, dual tobacco-cannabis users, tobacco policy researchers

Cannabis co-users less likely to switch from cigarettes or attempt quitting

What the researchers found

Participants who reported past-30-day cannabis co-use (N=56) smoked significantly more usual brand cigarettes during switch weeks than non-co-users (N=104, p=0.03) and were less likely to make a tobacco cessation attempt (p<0.05). This was true regardless of whether they were switching to very low nicotine cigarettes (VLNCs) or e-cigarettes.

Why it matters

Policies promoting switching from combustible cigarettes to reduced-harm alternatives (like e-cigarettes or VLNCs) may be less effective for cannabis co-users. Since about a third of the sample used both substances, this represents a substantial population that may need different tobacco cessation strategies.

The numbers in context

N=160 (56 cannabis co-users, 104 non-co-users). Cannabis co-users smoked more usual brand cigarettes during switch weeks (p=0.03). Cannabis co-users less likely to attempt tobacco cessation (p<0.05). Data collected September 2019-June 2022.

How the study worked

Secondary analysis of a mixed-design study. Adult cigarette smokers not motivated to quit were assigned study products (VLNCs, e-cigarettes, or no product) for 4 weeks and asked to switch from usual cigarettes during specific weeks. Active nicotine vs placebo patches were provided double-blind.

What this study cannot tell us

Secondary analysis not powered for this specific question. Small cannabis co-use subgroup (N=56). Self-reported cannabis use at baseline only. Cannot determine whether cannabis use directly caused resistance to switching or whether both behaviors share common underlying factors. Not generalizable to motivated quitters.

How to read the evidence

Moderate evidence from a secondary analysis of a randomized study, though limited by the small co-user subgroup and self-reported cannabis use.

When this study was published

2025 analysis of data collected 2019-2022 from a registered clinical trial (NCT04084210).

The bigger picture

Tobacco and cannabis are frequently co-used, and the smoking behaviors associated with each substance may reinforce each other. This study suggests that tobacco harm reduction strategies need to account for cannabis co-use, as people who use both substances may be more resistant to switching away from combustible cigarettes.

Questions still open

Does the physical act of smoking cannabis reinforce cigarette smoking habits? Would addressing cannabis use simultaneously improve tobacco cessation outcomes? Do cannabis co-users who switch to vaping nicotine also switch to vaping cannabis?

Common questions

Does cannabis use make it harder to quit smoking cigarettes?

In this study, people who used both cannabis and tobacco smoked more regular cigarettes when asked to switch to alternative products and were less likely to attempt quitting. The findings suggest cannabis use may reinforce cigarette smoking habits, making tobacco cessation more challenging.

Why might cannabis users have a harder time switching?

The study could not determine the exact mechanism, but possibilities include shared smoking rituals, combined use habits (like mixing tobacco and cannabis), and shared psychological factors that make people resistant to changing their substance use patterns.

Read the original research

Cannabis use among adults who smoke tobacco: Relations with switching from combusted cigarettes to e-cigarettes or very low nicotine cigarettes.

Drug and alcohol dependence, 275, 112821

View on PubMed ↗Publisher’s paper ↗

Citation

Piper, Megan E; Kaye, Jesse T; Piasecki, Thomas M; Yang, James J; Buu, Anne. (2025). Cannabis use among adults who smoke tobacco: Relations with switching from combusted cigarettes to e-cigarettes or very low nicotine cigarettes.. Drug and alcohol dependence, 275, 112821. https://doi.org/10.1016/j.drugalcdep.2025.112821