<p>This study investigates the causal relationship between social media (SM), environmental concerns, health concerns, and green purchase behavior (GPB). It explores the mediating roles of attitudes and social influence by integrating Social Impact Theory and the Theory of Planned Behavior. The aim is to address gaps in the literature regarding the growing significance of digital platforms in shaping eco-friendly consumer choices, particularly in emerging markets that have previously been overlooked. A quantitative approach was used to collect valid responses through a structured survey administered to SM users in Malaysia. Structural equation modeling (SEM) was employed to test the proposed causal relationships among the variables. The findings indicate that SM significantly predicts both environmental and health concerns. These concerns, in turn, positively influence attitudes and social influence, which ultimately drive GPB. The study confirms the indirect effect of social influence; however, the role of attitude was found to be insignificant. These insights can guide marketers and policymakers in leveraging digital platforms to enhance environmental awareness and health consciousness, thereby encouraging positive attitudes and social influence that promote sustainable behavior. This research makes a novel contribution by integrating environmental and health concerns and examining the joint mediating role of attitudes and social influence in the relationship between SM and GPB. Additionally, it extends previous models by offering a multi-dimensional perspective grounded in environmental psychology and communication theory.</p>