Assessing the Credibility of Health Information from Social Media Influencers: A Systematic Review and a Model of Young Adults' Evaluation Behaviors

ABSTRACT Guided by the dual‐processing model of information credibility, this systematic literature review analyzes how young adults evaluate the credibility of social media influencer (SMI) content, synthesizing findings from 30 peer‐reviewed studies published between 2015 and 2024. Findings show that credibility judgments are shaped by user motivations (e.g., social influence, platform dynamics), abilities (e.g., digital literacy, domain knowledge), and heuristics (e.g., source reputation, aesthetics). Eleven key constructs of SMI content credibility are identified, grouped under trustworthiness (e.g., honesty, relatability) and expertise (e.g., competence, authority). SMIs emerge as both trusted health communicators and potential sources of misinformation. The review emphasizes the importance of promoting digital literacy, promoting transparent platform design, and implementing regulatory safeguards to facilitate young adults' accurate assessment of health information online.