This research focuses on greenwashing in the fast-moving consumer goods (FMCG) sector, researching whether greenwashing practices affect the trust of customers, their brand loyalty, and the way they make purchasing decisions. Greenwashing, the act of misleading consumers about the environmental benefits of products, has become a significant concern as the importance of sustainability efforts in marketing continue to rise. This study explores whether FMCG consumers notice sustainability claims, and whether they find the difference between genuine sustainability efforts and greenwashing important, or relevant to their purchase decision. The research builds on consumer behavior theories, significantly the theory of planned behavior (Ajzen, 1991) and signaling theory (Spence, 1973), to grasp how consumers process sustainability signals, such as eco-labels, and if these signals influence their trust and purchasing behavior. Using qualitative methods, the study uses focus groups to collect insights from consumers about their perceptions of greenwashing and if it affects their trust in FMCG brands. The findings suggest that while consumers might want to engage in sustainable behavior, their decision is very dependent on visual cues, social context and perceived effort. Trust in the claims is then not shaped by only the messaging of brands, but also by peer discussions and digital tools, which furtherly highlight how important credibility, accessibility and informal learning in FMCG marketing is when it comes to sustainability.