AbstractEvaluating the presence of behavior change techniques (BCTs) in mHealth apps could be used to better understand what “active ingredients” contribute to outcomes. Despite the early onset of Anorexia Nervosa (AN) and the increasing use of mobile apps to seek mental healthcare among young people, BCTs underpinning mHealth apps targeting AN have never been systematically examined. This review systematically identified and analyzed BCTs underpinning apps targeted at reducing AN in young people in an attempt to understand their active components. Apps were searched and screened in Apple Store and Google Play. Six apps that met the inclusion criteria and were coded by trained researchers against the BCT Taxonomy V1. Overall, 22 of 93 possible BCTs were identified. The most common were “Information about health consequences,” “Social support (unspecified),” and “Information about antecedents”. Identified BCTs suggested potential overlaps with traditional clinical treatments for AN, such as cognitive behavioral therapy and family-based therapy. Further investigation is required to evaluate the apps’ usability and effectiveness.