Available data on the substances injected by users are based on self-reports collected in drug treatment registries or ad-hoc surveys. While these data are informative, they are often available only after some delay and are not analytically confirmed. Moreover, little is known about people who inject drugs that are not reached by drug services. The ESCAPE (European Syringe Collection and Analysis Project Enterprise) project seeks to complement existing data on substances injected by users, by providing timely and local information derived from the analysis of the residual content of used syringes.