Dr Charles Witzel is a Senior Research Fellow at Mahidol University and University College London. Charlie's research focuses on the health and well-being of LGBT people globally. He currently runs a programme of work on sexualised drug use among GBMSM in Thailand and contributes to ongoing research on mpox preparedness.

Background
Hi-fun (chemsex in Western settings) is increasingly visible in Southeast Asia, especially Thailand. Much harm reduction programming relies on Western conceptualisations of chemsex, obscuring critical variation related to local cultures, drug markets and legislative contexts. This study aims to develop a locally grounded definition of hi-fun among gay, bisexual and other men who have sex with men (GBMSM) in Thailand to inform service delivery and future research.

Methods
Focus groups (n=5) and in-depth interviews (n=6) (April-Sept 2024) included GBMSM (n=30) with experience of sexualised drug use, recruited from community organizations in Bangkok, Khon Kaen and Pattaya. Data were transcribed, translated and analysed thematically.

Results
The 30 participants were aged 25-47 years, 25 gay, ten living-with-HIV, seven born outside Thailand. Most (n=23) used crystal methamphetamine (ice) before/during sex in preceding 12-months, with fewer taking other drugs (ecstasy/MDMA=14, ketamine=12, cocaine=10, GHB/GBL=5).

Hi-fun involves intentionally combining sex and drugs with 1+ other man, underpinned by specific motivations including emotional drivers (pleasure, intimacy), socioeconomic considerations (status, building networks) and queer cultural participation (intergenerational learning, belonging).

Ice is central to hi-fun, with other drugs being less important. Injecting ice is increasingly normative; shifts from smoking were driven by declines in drug quality linked to the impacts of COVID-19 restrictions on drug markets and legal risks from carrying smoking equipment.

Online platforms are key to hi-fun organisation and used to verify partners in the face of police entrapment. To avoid discovery, hi-fun nearly universally takes place in a private setting and rarely in sex on premise venues.

Discussion
Hi-fun in Thailand is shaped by local context and defined as intentionally combining sex and crystal methamphetamine to enhance intimacy and pleasure with 1+ other man, facilitated by technology and usually in a private setting. Decriminalisation can reduce certain harms related to injection and police violence.