Background: Interest in and use of co-production in healthcare services and research is growing. Previous reviews have summarized co-production approaches in use, collated outcomes and effects of co-production, and focused on replicability and reporting, but none have critically reflected on how co-production in applied health research might be evolving and the implications of this for future research. We conducted this scoping review to systematically map recent literature on co-production in applied health research in the United Kingdom to inform co-production practice and guide future methodological research. Methods: This scoping review was performed using established methods. We created an evidence map to show the extent and nature of the literature on co-production and applied health research, based on which we described the characteristics of the articles and scope of the literature and summarized conceptualizations of co-production and how it was implemented. We extracted implications for co-production practice or future research and conducted a content analysis of this information to identify lessons for the practice of co-production and themes for future methodological research. Results: Nineteen articles reporting co-produced complex interventions and 64 reporting co-production in applied health research met the inclusion criteria. Lessons for the practice of co-production and requirements for co-production to become more embedded in organizational structures included (1) the capacity to implement co-produced interventions, (2) the skill set needed for co-production, (3) multiple levels of engagement and negotiation, and (4) funding and institutional arrangements for meaningful co-production. Themes for future research on co-production included (1) who to involve in co-production and how, (2) evaluating outcomes of co-production, (3) the language and practice of co-production, (4) documenting costs and challenges, and (5) vital components or best practice for co-production. Conclusion: Researchers are operationalizing co-production in various ways, often without the necessary financial and organizational support required and the right conditions for success. We argue for accepting the diversity in approaches to co-production, call on researchers to be clearer in their reporting of these approaches, and make suggestions for what researchers should record. To support co-production of research, changes to entrenched academic and scientific practices are needed. Protocol registration details: The protocol for the scoping review was registered with protocols.io on 19 October 2021: https://dx.doi.org/10.17504/protocols.io.by7epzje.