Countering online marketing and user endorsements with enhanced cannabis warning labels: An online experiment among at-risk youth and young adults.

As cannabis legalization expands and online marketing intensifies, this study examines whether online social cues can amplify youth-targeted cannabis advertising and whether cannabis warning labels (CWLs) can counteract these influences. A U.S. online sample of 970 adolescents and 1776 young adults susceptible to cannabis use were recruited from Qualtrics in summer 2022. Each participant was randomly assigned to one of the 3 (CWLs: none vs. textual vs. pictorial) by 3 (comments: none vs. anti-cannabis vs. pro-cannabis) conditions in an online experiment. Participants were exposed to three online marketing posts promoting marijuana edibles (randomly selected from a large pool, N = 1260), each with either no warning label, a textual warning, or a pictorial warning (text and picture), and with either five comments (pro- or anti-cannabis in valence) or none. Results showed that among adolescents, pro-cannabis comments increased product appeal (vs. anti-cannabis comments: b = 0.18, p = .025; vs. no comments: b = 0.21, p = .021), and did so more than young adults. For adolescents, only pictorial warnings reduced product appeal (b = -0.20, p = .028). For young adults, both pictorial (b = -0.18, p = .002) and textual warnings (b = -0.12, p = .029) reduced product appeal. Furthermore, both textual (adolescents: b = -0.20, p = .004; young adults: b = -0.15, p = .005) and pictorial (adolescents: b = -0.30, p < .001; young adults: b = -0.18, p = .001) warnings reduced cannabis use intentions. Findings support requiring enhanced CWLs accompany online marketing ads.