Introduction Over the counter and prescription-only medication misuse is of concern. Little is known about the impact on friends/family who provide individuals with support. It is important to increase understanding to identify how substance misuse services (SMS) and others can better meet their needs. The aim is to explore the impact of over the counter and prescription-only medication misuse on friends/family and improve an understanding of how this may be reduced. Methods Ethical approval was obtained and confidential semi-structured interviews were undertaken with a modified grounded theory approach. Participants were recruited from community adult SMS in England. Verbatim transcripts underwent thematic analysis using NVIVO, and findings are reported in line with COREQ. Results Eight telephone interviews (62.5% female) included a variety of different friend/relative relationships. Data saturation was felt to have been achieved, and identified that friends/family were significantly impacted, in long-standing and varying negative ways. Five themes were identified: impact on finances; impact of managing side-effects/withdrawal symptoms; impact on relationships; treatment interventions and personal support. Especially due to the psychological burden, friends/family benefit from holistic support, including improved awareness of over the counter and prescription-only medication misuse and interventions from healthcare/SMS providers, social services, affected others and their personal support network. Relationships where honesty and openness are encouraged, enable friends/family to provide more support and advocacy. Conclusions Care providers should include friends/family when delivering holistic interventions. They should be vigilant for safeguarding issues and the impact on children, and improve approaches to withdrawal symptom/side-effect management, medicines optimisation and service responsiveness. Future research should include more participants and other SMS.