The rapid proliferation of social media platforms has fundamentally transformed consumer purchase pathways, giving rise to social commerce as a pivotal mechanism through which brands establish and extend their market presence. This study empirically investigates the role of social commerce in driving brand growth among Generation Z (Gen Z) digital consumers in India. Data were collected from 300 respondents aged 18–29 years through a structured online survey employing five-point Likert scale instruments. The study examines five dimensions: platform preference for brand discovery, the influence of engagement metrics on purchase intention, the efficacy of influencer marketing, trust-building mechanisms within social ecosystems, and their collective impact on brand loyalty. Multiple regression analysis reveals that trust mechanisms (β = 0.412), influencer credibility (β = 0.384), and platform engagement (β = 0.291) together account for 68.4% of the variance in Gen Z brand growth outcomes (R² = 0.684; F = 213.42; p < 0.01). Findings confirm that micro-influencer credibility, verified user-generated content, and seamless in-app transaction infrastructure are the most decisive predictors of sustainable brand preference. The study contributes actionable insights for digital marketers seeking to optimize social commerce strategies for India’s largest emerging consumer cohort.