Abstract Introduction There are growing concerns about the misuse of over the counter (OTC) and prescription only medication (POM), due to the associated negative socioeconomic and health implications1. To improve care delivery, stigma needs to be addressed and more needs to be known about the perspectives of staff who are working in substance misuse services (SMS)2. Aims To use confidential semi-structured interviews, to explore the experiences of community English SMS staff who have supported adults that have misused OTC/POM. Methods This research was conducted across five community adult English SMS operated by a national treatment provider. Individuals were eligible for participating in semi-structured interviews if they had current experience of working in a community SMS role which involved supporting adults who had misused OTC/POM, were at least 18 years of age and provided informed consent. Potential participants self-identified as being eligible and interested in being included, after receiving the participant information sheet. The interviews explored their experience of working in SMS and supporting people who have misused OTC/POM, and potential changes to current SMS provision. Thematic analysis of the audio-recording transcripts was undertaken using NVivo®. This research was funded by a Research Award from Pharmacy Research UK and the College of Mental Health Pharmacy [PRUK_CMHP-2019-2-RG]. This research was approved by Humankind/EDP and Aston University’s Life and Health Sciences Ethics Committees (ID#1655). Results Organising interviews was challenging due to pandemic-related work pressures, between October 2020 and January 2021. Thematic analyses of twenty SMS staff transcripts was undertaken and data saturation was thought to have been achieved. Three overarching themes were identified: characteristics of OTC/POM misuse; different groups of people; and negative experiences (with six sub-themes: lack of awareness of risk of harm; unmanaged health conditions; withdrawal symptoms; side-effects; problematic behaviours; and treatment pathways). Oral dependent use of opioids (especially codeine products), benzodiazepines and gabapentinoids predominated. Polypharmacy and the use of other substances sometimes occurred. OTC/POM misuse was associated with a wide range of adverse socioeconomic, physical, and psychological effects. Unmanaged withdrawal symptoms caused concern, contributed to perpetuating misuse, and sudden cessation in supplies created risks. Discussion and Conclusion This study had a unique focus on the experiences of third sector English SMS staff. OTC/POM misuse (and withdrawal symptoms) should be routinely enquired about during healthcare reviews, and tailored harm reduction, pharmacological and psychosocial interventions offered. Increased awareness, vigilance for associated safeguarding issues, and more training is required. SMS should sensitively consider how to incorporate the views of staff with lived experience to further optimise service delivery co-production. As staff were all employed by the same SMS provider, future research, conducted in SMS operated by other providers, and covering a wider geography, may enable more information to be shared, more participants to be recruited, and the results more generalisable. Repeat interviews and member-checking may improve assurance in the findings. The possible need for different SMS for those who only misuse OTC/POM without exacerbating stigma requires further exploration. Future research should identify if demographic characteristics and treatment needs differ by OTC/POM type.