Background and Aims: Global changes in cannabis legislation have raised concerns about the potential impact of cannabis advertisements on increased cannabis consumption and intentions to use. This systematic review and meta-analysis evaluated the relationship between self-reported cannabis advertisement exposure on various media platforms and both cannabis use and intentions to inform public health policies and interventions.

Methods: A comprehensive search was conducted in PubMed, Scopus, and PsycINFO in 2024. Studies were included if they measured exposure to cannabis-related media (e.g., television, radio, print, billboards, point-of-sale, social media) and assessed cannabis consumption or intentions to use as outcomes. Three types of exposure were examined, including (1) general cannabis advertising (a composite measure including billboards, storefront/sidewalk, magazines, social media and any other type of advertising avenues), (2) internet/social media advertising, and (3) storefront/sidewalk advertising. Eligible English-language studies were observational (cross-sectional, case-control, cohort, and longitudinal) or randomised controlled trials with quantitative results. Meta-analyses were conducted using random-effects models.

Results: From 2,588 identified records, 22 studies conducted in the U.S and Canada (age range 11-65+ years) were included. Ten cross-sectional studies were eligible for meta-analysis. Based on methodologically comparable studies, three separate meta-analyses were conducted examining general, internet and storefront/sidewalk cannabis advertising exposure. General cannabis advertising exposure was significantly associated with cannabis use (aOR = 1.67 [1.27, 2.21]), while exposure to storefront/sidewalk advertising showed no significant association (aOR = 1.25 [0.95, 1.66]). Exposure to internet cannabis advertising was significantly associated with cannabis use (aOR = 3.38 [1.07, 10.66]). Most of the studies quality demonstrated to be of good (48%) or satisfactory (43%) quality with two studies deemed of unsatisfactory (10%) quality.

Conclusion: This review demonstrates a positive association between self-reported cannabis ad exposure and cannabis consumption and intention to use, particularly in adolescents and young adults. These findings underscore the need for regulations to protect youth from exposure to cannabis advertising. Further research is needed to assess the effectiveness of variations in advertising policy across diverse settings using longitudinal designs .