Background Online drug markets are expanding the boundaries of drug supply including the sale and purchase of image and performance enhancing drugs (IPEDs). However, the role of the internet in IPED markets, and in particular the ways in which these substances are supplied via the surface web, has rarely been considered. This article examines the online IPED market in order to inform drug policy and to provide a nuanced understanding of retailers involved, particularly exploring the relationship between buyers and sellers. Methods This paper is based on two extensive research projects conducted in the Netherlands and Belgium. The first project focuses on muscle drugs and is based on 64 IPED dealing cases, semi-structured interviews with authorities (N = 32), and dealers (N = 15), along with an analysis of 10 steroid-selling websites. The second research project primarily focuses on weight loss drugs and sexual enhancers in the Netherlands, and relies on interviews with authorities (N = 38), suppliers (N = 30), and consumers (N = 10), analysis of 69 criminal case files, and an online analysis. Results In the literature, the illicit online sale of IPEDs is generally associated with illegal online pharmacies that try to mislead buyers. While confirmed in our research, we also illustrate that there are online suppliers who invest in customer relationships and services, and that users are aware of the illegal nature of their business. These e-vendors incorporate a ‘social supply business model’ by providing the best possible service to their customers and attempting to minimise risks in order to attract, satisfy and maintain customers. Conclusion As it is likely that users will continue to make use of the internet to order IPEDs, regardless of closing down selling websites, it is first of all important to counteract these online sources by educating all types of consumers and providing harm reduction services.