Mobile phones have become one of the most unsustainable consumer goods. Social and environmental risks are found throughout the whole lifecycle of mobile phones. This chapter introduces the notion of lifecycle thinking to take sustainability beyond the product towards the larger product-system. Design can play a central role creating sustainable product lifecycles, but is constraint by other modes of regulation, such as law, social norms, and market. This paper explores the opportunities and limitations of design as regulation. The relational concepts of script and affordance help to provide a non-deterministic account of design as regulation. The particular case of the Fairphone 2, a smartphone designed with social and environmental values, will be discussed to investigate design as regulation. The notions of regulatory ecology and regulatory patching are introduced as tools to explore opportunities for constructing a more desirable regulatory regime Keywords. architectural regulation. circular products. Fairphone. lifecycle. planetary boundaries. rebound effect. regulatory ecology 1 Regulation (EC) No 1907/2006 of the European Parliament and of the Council of 18 December 2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), establishing a European Chemicals Agency 2 The ISO 14000 family of standards provides practical tools for companies and organizations of all kinds looking to manage their environmental responsibilities. 3 ISO 26000 provides guidance on how businesses and organizations can operate in a socially responsible way. This means acting in an ethical and transparent way that contributes to the health and welfare of society. 4 Directive 2009/125/EC of the European Parliament and of the Council of 21 October 2009 establishing a framework for the setting of ecodesign requirements for energy-related products. Directive 2010/30/EU of the European Parliament and of the Council of 19 May 2010 on the indication by labelling and standard product information of the consumption of energy and other resources by energy-related products.