The Impact of Influencer-Brand Congruence on Consumer Trust and Purchase Intention in Health Product Endorsements

The rise of social media has transformed how consumers engage with brands, particularly through the growing influence of social media personalities. In health and wellness marketing, influencers are often selected based on their appearance, lifestyle, and perceived alignment with brand values. However, little empirical research has examined the specific role of visual-based congruence between influencers and health-related brands in shaping consumer trust and purchase intention. While prior studies highlight the importance of influencer credibility, the mechanisms by which visual congruence and parasocial identification affect consumer behavior remain underexplored. This thesis explores: To what extent does influencer-brand congruence impact consumer trust in health products and their purchase intention? Drawing on social identification theory and parasocial interaction, the study hypothesizes that higher influencer-brand congruence will lead to greater trust and intention to purchase, and that this relationship is mediated by the consumer's emotional connection and how they identify with the influencer. To test this, a between-subjects experimental design was conducted with 165 participants who were randomly assigned to view either a high-congruence, low-congruence or neutral influencer-brand pairing. Participants completed a structured online survey measuring influencer credibility, trust, parasocial relationship, aspirational identification, and purchase intention. The data was analyzed using ANOVA and mediation analysis with PROCESS macro. The results of the study revealed no statistically significant direct effects of influencer-brand congruence on consumer trust or purchase intention, as indicated by ANOVA and regression analyses. Similarly, parasocial relationship did not significantly mediate the relationship between congruence and either trust or purchase intention, suggesting that emotional familiarity alone was insufficient to drive these outcomes in the tested context.However, the analysis revealed that aspirational identification significantly mediated the relationship between influencer-brand congruence and both consumer trust and purchase intention These findings suggest that aspirational identification, rather than congruence or parasocial ties alone, plays a crucial role in building trust and purchase intention. Marketers should prioritize influencers who evoke aspirational appeal to enhance campaign effectiveness in the health sector.