This study analyzes how Oficina Muda develops socially and environmentallyresponsible solutions for the reuse of textile waste, positioning itself as a concrete alternativeto the impacts generated by fast fashion. Using a qualitative and exploratory approach - based on interviews, on-site observation, and content analysis - the research investigatesthe company s business model, its circularity practices, and its internal and externalchallenges. The theoretical discussion integrates concepts of slow fashion, circular economy,upcycling, sustainable marketing, and shared value. The results show that Muda combinesenvironmental impact, social inclusion, and economic feasibility, although it faces cultural,operational, and institutional barriers that limit the expansion of circularity in the fashionsector. The study demonstrates that structured reuse practices can contribute to reducingtextile waste and inspire more responsible models within the Brazilian fashion industry.