The global demand for eco-friendly cosmetic products has increased significantly due to rising environmental awareness and sustainability concerns. However, limited empirical research has comprehensively explained the psychological and informational mechanisms influencing consumers’ purchasing behavior in this context. This study addresses this gap by integrating the Theory of Planned Behavior (TPB), Trust Theory, and Alphabet Theory to examine the key determinants of purchasing behavior for eco-friendly cosmetics. The proposed model investigates the effects of Product Awareness, Environmental Concern, Product Information, and Trust on consumer Attitude and Actual Purchasing Behavior. A quantitative research design was adopted using survey data collected from 380 consumers with prior experience purchasing cosmetic products. Data were analyzed using Confirmatory Factor Analysis (CFA) and Structural Equation Modeling (SEM) to evaluate measurement reliability and structural relationships. The results demonstrated strong reliability and validity, with Cronbach’s Alpha, Composite Reliability, and Average Variance Extracted exceeding recommended thresholds, while discriminant validity was supported using the Fornell–Larcker criterion and HTMT ratios. Structural model findings revealed that Trust is the strongest predictor of Attitude (β = 0.44), followed by Product Awareness (β = 0.29), Environmental Concern (β = 0.24), and Product Information (β = 0.21). Attitude significantly influences Actual Purchasing Behavior (β = 0.47) and partially mediates all relationships. The model explains 57% of Attitude and 63% of Actual Behavior.
