This study aims to map existing literature describing how people with lived experience of self-harm have engaged in codesigning self-harm interventions, understand barriers and facilitators to this engagement, and how the meaningfulness of codesign has been evaluated.

Scoping review by Joanna Briggs Institute methodology. A protocol was published online (http://dx.doi.org/10.17605/OSF.IO/P52UD).

PubMed, Embase, PsycINFO, Web of Science, Cochrane Library, PROSPERO, ClinicalTrials.gov and relevant websites were searched on 24 December 2022 (repeated 4 November 2023).

We included studies where individuals with lived experience of self-harm (first-hand or caregiver) have codesigned self-harm interventions.

Results were screened at title and abstract level, then full-text level by two researchers independently. Prespecified data were extracted, charted and sorted into themes.

We included 22 codesigned interventions across mobile health, educational settings, prisons and emergency departments. Involvement varied from designing content to multistage involvement in planning, delivery and dissemination. Included papers described the contribution of 159 female, 39 male and 21 transgender or gender diverse codesigners. Few studies included contributors from a minoritised ethnic or LGBTQIA+ group. Six studies evaluated how meaningfully people with lived experience were engaged in codesign: by documenting the impact of contributions on intervention design or through postdesign reflections. Barriers included difficulties recruiting inclusively, making time for meaningful engagement in stretched services and safeguarding concerns for codesigners. Explicit processes for ensuring safety and well-being, flexible schedules, and adequate funding facilitated codesign.

To realise the potential of codesign to improve self-harm interventions, people with lived experience must be representative of those who use services. This requires processes that reassure potential contributors and referrers that codesigners will be safeguarded, remunerated, and their contributions used and valued.