The design field is in a constant state of evolution, driven by the development of frameworks, methodologies, and tools that shape the products, services, and technologies we use daily. Among these, Human-Centred Design has become one of the most influential frameworks in recent decades, focusing on placing people at the core of the design process by prioritising their needs and experiences through a collaborative, empathetic approach. While this model has proven invaluable in creating solutions that enhance people's lives and boost user engagement, it has faced criticism for its narrow focus on individual well-being, often overlooking the wider social and environmental impacts on the ecosystem. In response, Humanity-Centred Design has emerged, expanding the design lens to include environmental and social considerations that tackle broader global challenges. This study delves into how Transformative Enterprises, which aim to address pressing global issues, implement the Humanity-Centred Design model. Through a multiple-case study of two start-ups promoting eco-conscious consumption, the research identifies key differentiating strategies such as diversifying stakeholders for a more inclusive design process, leveraging enablers of behavioural change, setting mission-driven metrics for decisionmaking, and adopting marketing and positioning strategies that raise awareness, foster community engagement, and communicate their mission in innovative ways. These findings lay a critical foundation for the practical implementation of the Humanity-Centred Design model, bridging the gap between theory and practice by offering a more inclusive and transformative approach to the design process.