In a world increasingly driven by environmentally conscious consumer behaviour, the effects of product labelling on sustainable purchase intentions remain a critical area of marketing research. In order to understand the complex relationship between labels and consumer decisions, this research explores the interesting dynamics of label influence using theories including Goal-framing Theory, Reasoned Action Theory, the SHIFT model, and Information Asymmetry. This research reveals, by using a thorough method that combines quantitative surveys with experimental methods, that even environmentally conscious consumers find it difficult to distinguish between legitimate and copycat certificates. The results strongly imply that consumers are much more likely to purchase goods with legitimate certificates than those with copycat certificates or none at all, when information asymmetry doesn’t exist. This realisation creates new opportunities for NGOs, government departments, and marketers to create better and more knowledgeable labelling plans, which will increase consumer trust and promote more environmentally friendly purchase behaviours.