The hype surrounding the emergence of nanotechnology proved extremely effective to raise public attention and controversies in the early 2000s. A proactive attitude prevailed resulting in the integration of social scientists upstream at the research level, research programs on Ethical, Legal and Societal Impacts, and various public engagement initiatives such as nanojury and citizen conferences. Twenty years later, what happened to the promises of SHS integration and public engagement in nanotechnology? Was it part of the hype, one of the many (...) promises made by the champions of nanotechnology initiatives that never materialized? As a contribution to this broad question, this paper focuses on public engagement initiatives in France and ventures some general reflections on their fate. I will first report, from an insider’s perspective, the public debates conducted by a civil society organization VivAgora, in the national context of fierce controversies. Then I will describe the permanent forum NanoRESP opened in 2013 when nano controversies waned out. On the basis of this case study, I will argue that the STS ideal of co-production of science and society gradually gave way to a more modest co-learning process between stakeholders in the 2010s. (shrink)