The problematic use of psychoactive substances has adverse consequences for people's lives and requires on-going investigation of experiences of onset, course and resolution in order to better inform theoretical understanding, particularly with regard to the use of club drugs and novel psychoactive substances. In turn, this may influence treatment approaches. GHB/GBL, frequently termed 'G', is one such substance, with problematic use resulting in increased presentations at A&E departments and at substance dependence clinics across Europe. The aim of the present study was to explore problematic G use as experienced by people who had presented for treatment, in Ireland, using interpretative phenomenological analysis (IPA). IPA was selected in recognition of the lack of previous research on the experience of problematic use of G and in the context of an evolving understanding of what constitutes problematic substance use. A purposive and homogenous sample of seven people, five gay males and two straight females, who had presented for treatment for 'G' substance use disorder to a community-based drug team, participated in semi-structured interviews. Three superordinate themes reflecting the participants chronological development of problematic 'G' use and early recovery were fully developed and presented-(1) early use: "I was part of that gang that took G"; (2) daily use: "It's like insidious; it just weaves into your everyday life"; and (3) early recovery: "my priorities are changing". This study supports the interactive role of community, self-identity, personal vulnerability and substance effects in the development, maintenance and recovery from problematic G use. Findings are discussed in the context of gay community health, the role of chemsex in problematic substance use and the need for public health providers to engage with novel psychoactive substance use and the health and well-being effects of chemsex.