Improved collaboration and communication between public health practitioners and academia could enhance the flow of research evidence into policy and practice. Embedded researchers present one type of intervention with the potential to bridge the research-implementation gap through their dual affiliations with decision makers and academia. Although embedded researcher posts are garnering increasing attention in public health, there remains a need to understand the mechanisms through which they may promote the translation of evidence into practice. To address this gap, we conducted a processes evaluation incorporating data from seventeen semi-structured interviews with embedded researchers in local government public health teams across England. We aimed to expand theoretical understandings of embedded researchers in public health through providing a detailed conceptualisation of the mechanisms shaping the early stages of their roles. Interviews with embedded researchers were conducted from late 2021 to spring 2022. Our results suggest that the initial months of embedded researcher roles are defined by a lengthy embedding phase centred on building trust and gathering contextual knowledge. This phase forms the foundation on which these interventions are built. We identified seven categories of outputs delivered by embedded researchers which primarily revolved around building research capacity and addressed many of the primary barriers limiting research activity in public health. Improvements in research awareness, interest, and involvement reflected early changes in local research cultures. However, our results align with previous work suggesting that changing an organisational research culture is a long-term process. Expectations for embedded researchers should thus be proportionate to the seniority and scale of the post and we add our voice to calls for sustained investment in these valuable interventions. Further examination of how embedded researcher roles evolve over time in public health is necessary to broaden understandings of the concept of embeddedness in these settings.