Perceptions of Cannabis Vaping Advertising Messages and Warnings Among US Young Adults

BACKGROUND: Cannabis vaping prevalence and marketing has increased, but limited research has assessed effects of specific advertising messages, warnings, or their combinations on young adults' perceptions. This study aimed to advance this research. METHODS: In 2024, 3581 US young adults aged 18 to 34 (40.8% reporting past-month use) participated in an online survey-based experiment using a 2 × 4 factorial design (advertising message: psychological effects vs flavors; warning: none, adult-use, intoxication, vape-specific) and then reported on 5 perception outcomes: addictiveness, harm, cautiousness, appeal, and interest (0 = not at all to 7 = extremely). Multivariable regression assessed advertising message, warning, and message-by-warning interactions in relation to outcomes, overall and by past-month use status. RESULTS: Among the total sample and among participants reporting no cannabis use, there were no main or interaction effects of advertising message or warning conditions. Among participants reporting use, adult-use (vs no) warning exposure was associated with lower addictiveness and cautiousness; intoxication (vs no) warning exposure was associated with lower harm. A significant interaction indicated that participants reporting use who were exposed to both psychological effects (vs flavors) advertising messages and intoxication (vs no) warnings reported greater appeal, whereas those exposed to both flavors (vs effects) advertising messages and intoxication (vs no) warnings reported lower appeal. CONCLUSIONS: These findings highlight the importance of understanding how advertising messages may affect how warnings are interpreted (or vice versa), strengthening the evidence base informing advertising restrictions and warning requirements, and elucidating the mechanisms driving the differences among young adults who use versus do not use cannabis.