Abstract: Background: Health research in the UK requires patients, those with lived experience and members of the public to be involved in designing and shaping research: many of them have reported that their comments and suggestions are not always acknowledged, and they do not know if their input has been used or is useful. The benefits of feedback from researchers not only create motivation for further involvement but aids learning and development, as well as recording impact. The aims of this study were to improve the feedback experience of Patient and Public Involvement (PPI) contributors. Co-produced feedback processes were designed and implemented in order to change feedback from researchers to PPI contributors in six PPI groups in England. Methods: An explanatory mixed methods sequential study design was utilised with a comparative questionnaire survey (administered 20 months apart), interviews and a focus group with PPI leads, researchers and PPI contributors. Patient and Public Involvement contributors were involved from initial idea, study design, data analysis through to dissemination. Results: Co-designed feedback processes were introduced in five of the six PPI groups and there was an overall increase in the frequency of feedback over the period studied. The enablers and barriers to implementing feedback processes were identified, which included the importance of wider institutional level support. PPI leads need to have dedicated time and acknowledge feedback as part of their role. The importance of individual feedback processes designed by, and for each PPI group, rather than a generic one, was also identified as key to successful implementation. Conclusion: The role of the PPI lead is an important facilitator in improving feedback but can easily be overlooked and has been described as invisible. PPI leads can perform an essential bridging role between researchers and members of the public. This study has shown that PPI feedback processes can be implemented if they are part of embedded PPI with explicit expectations, facilitated by a dedicated PPI lead role with sufficient support and resources. The findings have implications beyond this particular study, particularly for those involved in undertaking and funding health and social care research.