PurposeYoung adults’ e-cigarette use is a leading public health concern. Using messages from credible sources can help improve message acceptance, yet little research has examined the role of source credibility on young adults’ responses to e-cigarette education messages. MethodsWe examined the impact of source on young adults’ perceptions of e-cigarette education messages and e-cigarettes. In July 2022, we conducted an experimental study using an online sample of young adults (N=459, Mage=24.6) who were randomized to one of three source conditions: expert, friend, or influencer, and viewed e-cigarette education messages. We used one-way ANOVA to estimate the association between the conditions and outcomes (perceived source credibility, message trust, curiosity, use interests, perceived message effectiveness, beliefs, harm perceptions, and intentions to refrain). ResultsThe expert condition was associated with significantly higher perceived source credibility (vs. friend, influencer; p<0.001), message trust (vs. friend, influencer; p<0.001), and curiosity (vs. influencer; p’s<0.05). ConclusionsPublic health campaigns may leverage health experts to deliver e-cigarette education messages targeting young adults to improve effectiveness of the messages.