Consumer health information technology, such as mobile health applications (mHealth), enable consumers adopt healthy behaviours and improve health outcomes. We take a closer look at use concepts to understand how mHealth use facilitates behaviour change. We review the mHealth literature in information systems (IS) and health IS journals and find that superficial mHealth use concepts (e.g. binary and duration of use) dominate this literature stream. In line with contemporary IS research, we suggest that rich and theoretically-driven concepts of mHealth use can help to better understand what users do with mHealth and how this affects relevant outcomes. We take a social cognitive theory (SCT) perspective to conceptualize mHealth deep structure use, a rich concept of use centred on the extent to which tasks represented in mHealth facilitate behaviour change. This paper contributes to IS research in three key ways. First, we review mHealth literature and identify use concepts that have been employed to explain effects on outcomes. Second, we provide a theoretically-driven mHealth deep structure use concept from a SCT perspective. Third, we offer a conceptual lens that captures how mHealth deep structure use facilitates behaviour change. Future research will empirically evaluate aspects developed in this mHealth deep structure use concept.