Prescription Drug Promotion by Social Media Influencers: A Systematic Scoping Review Abstract Importance: Prescription drug promotion by social media influencers (hereinafter influencers) is a growing phenomenon that raises concerns about misleading advice, insufficient regulatory oversight, and ethically problematic marketing practices. Understanding the scope and risks of influencers' promotional activities is essential to protect public health. Objective: To systematically review existing research on influencer prescription drug promotion, with a focus on identifying recurring themes, regulatory gaps, and opportunities for intervention. Evidence review: This systematic scoping review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline. The search strategy was developed with a health sciences librarian and preregistered on Open Science Framework. English-language articles from peer-reviewed journals were retrieved from the Medline, Communication & Mass Media Complete, CINAHL Complete, PsycInfo, Web of Science, Business Source Complete, Scopus, and Cochrane Library databases, covering research conducted in diverse online and health care contexts worldwide from 2004 to 2024. Searches used key terms related to influencers, social media, and prescription drugs, completed on March 13, 2024. Included studies underwent thematic analysis. The primary outcomes included concerns related to accuracy (misinformation), transparency (disclosure practices), and persuasiveness (personal and parasocial narratives) of prescription drug promotion by influencers. Findings: Twelve articles met inclusion criteria (8 empirical and 4 theoretical), addressing topics such as contraceptive advertising, performance-enhancing drugs, and broader pharmaceutical promotion. Methods included content analyses, interviews, and experiments. Three recurring themes emerged: (1) misinformation stemming from influencers' limited expertise in the context of audiences' low health literacy; (2) weak regulatory oversight and inconsistent disclosure practices; and (3) parasocial narratives that blur distinctions between personal testimony and paid promotion. Conclusions and relevance: This systematic scoping review study of prescription drug promotion by influencers found that such promotion carried risks of inaccurate or misleading advice, often amplified through personal and emotionally resonant narratives in an environment with limited oversight and enforcement. Despite the small and fragmented evidence base, these findings highlight the urgent need for updated regulatory guidance, standardized and enforceable disclosure requirements, stronger platform accountability, and targeted digital literacy initiatives. Policymakers and researchers should act proactively to safeguard public health. Publication types Scoping Review MeSH terms Humans Marketing* / methods Prescription Drugs* Social Media* Substances Prescription Drugs