Introduction: The cosmetic industry provides several plastic packaging problems for the environment. It has been shown that 120 billion units of packaging are produced annually by the global cosmetic industry. Campaigns for environmentally friendly products for cosmetic packaging are growing. This study aims to determine the effect of plastic packaging on the environment. Methods: Research on environmentally friendly cosmetic products was conducted by distributing online questionnaires distributed through online platforms. The total respondents of the questionnaire were 215 generation z people who were then analyzed with PLS-SEM. Findings: The results showed that personal norms have a significant effect both directly and mediated by green purchase intention on green purchase behavior. Conclusion: However, environmental concern does not have a significant effect, even though it has been mediated by green purchase intention on green purchase behavior in environmentally friendly cosmetic products in Indonesia. Novelty/Originality of this study: This study explores the factors influencing the purchasing behaviour of eco-friendly cosmetic products among Indonesian Generation Z and reveals the critical role of personal norms in driving sustainable consumption. This study provides valuable insights for the cosmetic industry in developing effective marketing strategies for eco-friendly products.