The paper investigates the regulatory processes in the sharing economy, an economic sector in which the technological factor plays a crucial role in shaping the regulatory intervention both by private and public actors. The aim is to evaluate, from a constitutional perspective, whether it is possible to rely on self-regulation by sharing economy actors (i.e. platforms and users). After having defined sharing economy, the arguments in favour of self-regulation and reputational mechanisms at the dawn of the sharing economy are outlined on the basis of existing literature and guidance instruments issued by the European Commission. Then, focusing on the case of the home-sharing platform Airbnb, how the regulatory processes tend to move beyond the approach based on self-regulation is shown. The paper also provides a practical and theoretical criticism of online reputational mechanisms as regulatory tools. The conclusion is that self-regulation alone is not an appropriate instrument to regulate sharing economy. Self-regulation is not fit to strike a balance between the interests of sharing economy actors on the one hand and the interests of other citizens and the public on the other.