<jats:sec> <jats:title>Purpose</jats:title> <jats:p>We investigate the effect of social capital (SOC) and interactions on buying intentions through the mediating impacts of knowledge sharing (KS) and the dual effects of health risk.</jats:p> </jats:sec> <jats:sec> <jats:title>Design/methodology/approach</jats:title> <jats:p>SmartPLS 4.1.0.9 is used for the Partial Least Squares Structural Equation Modeling (PLS-SEM) technique.</jats:p> </jats:sec> <jats:sec> <jats:title>Findings</jats:title> <jats:p>Our findings present that SOC and interactions have a positive impact on KS. KS plays the mediating role, while health risk affects both directly and indirectly the buying intentions.</jats:p> </jats:sec> <jats:sec> <jats:title>Practical implications</jats:title> <jats:p>Our findings recommend that firm managers should understand the significant role of SOC and interactions in enhancing purchase intentions (PI) through KS. They should pay attention to an open environment of KS for obtaining innovative products, provide credible and valuable information for customers to achieve lower health risk concerns, thereby improving trust and enhancing PI.</jats:p> </jats:sec> <jats:sec> <jats:title>Originality/value</jats:title> <jats:p>The examination of the mediating effects of KS and the dual effects of health risk contributes to the existing literature. We also expand the literature by analyzing the influence of KS on novelty and the impact of health risk on KS. We contribute to both theoretical expansions and practical tactics in the sphere of information administration, innovations and customer activities.</jats:p> </jats:sec>