PurposeThe rapid growth of semaglutide use for weight loss has been accompanied by a proliferation of patient-shared experiences and non-evidence-based claims on video platforms. This unchecked information environment poses significant risks to public health, including potential self-medication and misunderstanding of treatment risks, underscoring the urgent need to evaluate the quality of semaglutide-related video content to safeguard digital health literacy. This study assesses the quality, reliability, and user engagement of semaglutide-related short videos on TikTok and Bilibili.ApproachThis cross-sectional study analyzed the top 100 semaglutide-related videos from TikTok and Bilibili, using keyword searches. Videos were evaluated using JAMA benchmark criteria, Global Quality Scale (GQS), and DISCERN tools.SettingRetrieving top 100 videos from TikTok (Mar 4, 2025) and Bilibili (Mar 8, 2025) using "" (Semaglutide) as the search keyword.Participants200 videos and their characteristics.ResultsAmong 200 videos, no statistically significant inter-platform differences in JAMA, GQS or DISCERN scores were observed. Non-professional organizations achieved higher JAMA scores than individual creators (< .01). Medical information videos scored higher than personal experience content (< .0001). Engagement metrics (likes) correlated weakly with quality (r = 0.151,< .05), while longer videos were associated with higher DISCERN scores (r = 0.273,< .001) but not increased engagement.ConclusionsSemaglutide-related videos on TikTok and Bilibili show moderate quality, with medical professionals and institutions producing more reliable content. However, user engagement remains a poor indicator of quality. These findings call for platform governance to algorithmically promote evidence-based content and verify credible creators, while public health efforts should steer user attention from popularity to credibility, thereby protecting informed decision-making.