Abstract: The growing significance of sustainability has compelled the FMCG and consumer goods firms to consider using social media as one of the main means of reaching consumers and advocating environmentally friendly behavior. This paper researches how the Social Media Engagement, User-Generated Content and Influencer Persuasiveness affect consumer Purchase Intention when the mediating variable is Brand Trust. Structured questionnaire was used to gather data on 202 subjects in Chennai city. Regression-based mediation was used according to Baron and Kenny method, and the value of indirect effects was tested with the help of the Sobel test.

The findings demonstrate that Social Media Engagement and User-Generated Content have a significant role in Purchase Intention both directly and indirectly, mediated by Brand Trust, which implies partial mediation. Influencer Persuasiveness, in its turn, has a direct impact on Purchase Intention, and does not affect Brand Trust. The predictive power of Brand Trust itself was established as high.

The paper emphasizes the role of integrating trust-building, including consumer engagement and peer content, and persuasive influencer-based approaches to enhance sustainable branding activities. The results offer practical implications to FMCG companies in developing a viable social media strategy that create credibility, trust, and sustainable consumer behavior.

Keywords: Sustainable branding, FMCG, Social media, Brand trust, Influencer persuasiveness, User-generatedcontent, Purchase intention, Chennai

Downloads: | DOI: 10.17148/IARJSET.2025.12845