Assessing the quality and reliability of health information on GLP-1 receptor agonists on TikTok and Bilibili: a cross-sectional analysis of the public health infodemic.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) receptor agonists have transitioned from clinical tools for diabetes to a global cultural phenomenon for weight loss, triggering an "infodemic." While previous studies have characterized this landscape on Western platforms, the digital health ecosystem in China remains distinct. China is currently navigating a unique market shift driven by the June 2025 approval of the domestic dual agonist mazdutide, an impending 2026 patent cliff for semaglutide, and a specific market for counterfeit products. OBJECTIVES: To assess and compare the quality, reliability, and content completeness of health information regarding GLP-1 agonists on China's two dominant video platforms, Douyin (the Chinese version of TikTok) and Bilibili; to examine how platform architecture and regulatory context influence content reliability; and to contrast these findings with recent benchmarks from Western social media studies. DESIGN: Cross-sectional observational study. METHODS: A systematic search for "GLP1" was conducted on Douyin and Bilibili. Due to divergent algorithms, an asymmetric sampling strategy was used: all 106 videos returned by Douyin were screened, while the top 200 videos from Bilibili's default ranking were assessed. After applying exclusion criteria, 128 videos (56 Douyin, 72 Bilibili) were analyzed. Quality was evaluated using the modified DISCERN tool, Global Quality Score, and JAMA benchmarks. No human subjects were involved; therefore, ethical approval was not required. RESULTS: Bilibili videos were significantly longer and demonstrated superior quality, scoring significantly higher than Douyin videos on both the DISCERN (p < 0.001) and JAMA benchmark (p = 0.003). Unlike findings on TikTok and Instagram, where quality was uniformly low, Bilibili hosted high-quality, in-depth content comparable to patient education materials. However, a safety analysis revealed videos promoting fraudulent products that co-opt the drug's brand name, posing a severe risk unique to the unregulated domestic supply chain. CONCLUSION: The Chinese digital landscape exhibits a quality tier on Bilibili that is absent in Western short-video counterparts. While Bilibili serves as a reliable "digital library," Douyin remains a high-risk environment for misinformation and counterfeit sales. As China approaches the 2026 patent cliff, regulatory bodies must address the specific threat of fraudulent "GLP-1" branding on illicit products. TRIAL REGISTRATION: Not applicable.