Digital Harm Reduction: A Review of Current Uses of Social Media, Mass Media, and Mobile Health Applications for Safer Use and Substance Use Prevention

Abstract Introduction - Digital harm reduction has emerged as a critical public health strategy as substance use patterns and communication landscapes shift. Social media, mass media, and mobile health (mHealth) applications now play an increasingly central role in delivering accessible, rapid, and user-centered harm reduction information. Method - A comprehensive literature search was conducted across PubMed, Google Scholar, PsycINFO, ProQuest, and ScienceDirect for publications between 2015 and 2025. Search terms related to social media, mass media, mHealth, digital harm reduction, safer use, and substance use prevention were used. A supplementary targeted web search was used to identify additional commentary and practice-based resources. Results - Social media platforms such as TikTok, Instagram, Facebook, and YouTube support harm reduction by sharing accurate information, countering misinformation, and normalizing naloxone use through hashtags, storytelling, and influencer-led campaigns. Mass media campaigns deliver wide-reaching public health messages but vary in effectiveness based on message design and cultural relevance. mHealth applications such as the Digital Overdose Response System (DORS), ikeepr, and Unity Philly provide supervised use monitoring, life-skills training, mental health screening, and coordinated care, offering scalable and personalized digital support. Discussion - Findings demonstrate that digital platforms enhance reach, reduce stigma-related barriers, and complement traditional harm-reduction services. However, challenges persist, including algorithmic suppression, unequal digital access, misinformation risks, and ethical concerns related to privacy and data governance. Evidence for long-term effectiveness remains limited, with most tools showing stronger impact in short-term engagement and education. Conclusion - Digital harm reduction provides flexible, accessible, and scalable pathways for safer use education and early intervention, but should complement, not replace, traditional in-person services.