Significance Research shows that pictorial warning labels for cigarettes are more effective than text-only warnings, and preliminary work suggests that pictorial warnings could also be considered for electronic cigarettes (e-cigarettes). Pictorial warnings may be important for maximising their effectiveness among young people and enhancing the salience of the single nicotine addiction warning required for e-cigarettes to date in the USA. This study collected pilot data about the perceived effectiveness of draft e-cigarette pictorial warnings.

Methods Participants were 876 young adults (ages 18–29) recruited through Amazon Mechanical Turk who completed an online e-cigarette survey in 2018. Participants viewed and ranked five versions of the same e-cigarette nicotine addiction warning message—four pictorial and one text-only–on their perceived noticeability, likelihood of capturing young people’s attention, memorability, relevance to the addiction warning text and overall effectiveness in warning people about e-cigarette risks. For each outcome, presentation of the five warning versions was randomised. Pictorials included symbolic images of risk and addiction, and of priority audiences for the warning (ie, young people).

Results For all outcomes, pictorial warnings were ranked higher than the text-only warning, and the warning using a yellow triangle caution icon was ranked highest for all outcomes. The text-only warning was ranked as the least likely to be effective for all four outcomes in which it was assessed. Trends were similar for current e-cigarette users and non-users.

Conclusions Future research should assess perceptions and the appropriateness of pictorial imagery for e-cigarette warnings and test their efficacy against text-only warnings experimentally.