Background: Young adult sexual minority women (YSMW) report disproportionate e-cigarette (EC) use and low EC harm perceptions. Health messages that effectively communicate EC harms to YSMW are needed. We tested the effect of culturally targeted EC health messages with varying themes and image formats on attitudes and intentions to use ECs in this population.

Methods: N = 501 YSMW and nonbinary people assigned female at birth (AFAB) aged 18-30 years-old completed an online experiment. Participants were randomized into a control or one of nine experimental conditions in a 3 (theme: harms, wellness, pride) by 3 (image format: individual, couple, cartoon) study design. We modeled associations between message condition and message effectiveness, discouragement from vaping, change in feelings toward vaping, perceived threat, and intentions to abstain from vaping.

Results: Among YSMW and nonbinary people AFAB, harm and wellness themes discouraged vaping more than pride-themed messages (p's < 0.001). Harms messages resulted in worse feelings about vaping than wellness and pride messages (p's < 0.02). Images of couples were perceived as more effective than cartoon images (p = .008). Among current EC users, viewing images of individuals resulted in greater readiness to avoid ECs and higher intentions to abstain than the couple or cartoon conditions (p's < 0.001).

Conclusions: Message theme and image format were associated with YSMW and nonbinary people AFAB's EC attitudes and behavioral intentions. Future studies should evaluate how to optimize harms messages; including if wellness or pride messages can be re-framed to better affect EC use in this population.