PurposeChemsex-related drug use (CDU) is an escalating public health issue among men who have sex with men (MSM), associated with significant physical, biomedical and psychosocial harm. Few interventions exist to help MSM engaging in chemsex and little data exist on which to build. This cross-sectional analysis, using data from Antidote, the UK’s only lesbian, gay, bisexual, and transgender specialist drug service, aims to remedy this paucity of data.MethodsModified Poisson regression was used to assess associations between CDU and a range of health outcomes; CDU+ subanalysis disaggregated MSM by primary chemsex drug of concern; and HIV+ subanalysis investigated whether CDU was associated with self-reported treatment adherence, HIV seroconversion and other HIV-specific issues.FindingsCompared with CDU− MSM, MSM presenting for CDU were more likely to be HIV+, current or previous injectors, to have used postexposure prophylaxis in the last year, and have had ≥6 sexual partners in the last 90 days, though less likely to be hazardous alcohol consumers or to have experienced previous suicidal ideation (all p<0.0005). CDU+ subanalysis revealed health outcome differences—those selecting mephedrone were less likely to be hepatitis C+, HIV+, current or previous injectors, or to have experienced previous suicidal ideation (all p<0.0005), whereas those selecting methamphetamine were more likely (all p<0.0005, except suicidal ideation p=0.009).ImplicationsThis analysis shows MSM presenting for CDU are a heterogeneous high-risk population with unmet health needs. There is a need for standardised chemsex surveillance and for improved intersectorial working between sexual health and drug treatment services. Future research should investigate typological differences between MSM presenting for CDU.Originality/valueTo date, this is the world’s largest analysis of MSM seeking treatment for CDU. Further, the publication of ‘real-world’ service data is a valuable addition to the literature alongside surveys and recruited studies.

Men who have sex with men (MSM) who experience problematic chemsex are at high risk of acquiring HIV due to combined drug use and sexual behaviours. Pre-exposure prophylaxis (PrEP) could substantially reduce the risk of HIV transmission in this group of men. The aim of this study was to examine the biopsychosocial characteristics associated with PrEP use among HIV-negative MSM who have experienced problematic chemsex. This was a cross-sectional analysis of secondary data collected during client assessments at a specialist alcohol and drug service based within the United Kingdom. We compared the socio-demographics, substance use, sexual behaviours and mental health of MSM who reported ever using PrEP to those who reported never using PrEP. Statistical analysis was conducted using the Mann–Whitney U-test for continuous variables and Fisher’s exact test for categorical variables. Between August 2016 and July 2018, 165 HIV-negative MSM who engaged in chemsex had an assessment completed. Thirty-four per cent (n = 50/145) had ever used PrEP. The median age was 36 years (IQR: 30–42), 92% identified as gay (n = 152/165) and 79% were of white ethnicity (n = 130/164). The use of crystal methamphetamine was associated with higher levels of men ever using PrEP (40% versus 21%) (p= 0.047). Men who had ever used PrEP had a higher median number of sexual partners in the previous three months (20 versus 10) (p= 0.004) and had lower level of condom use in their sex lives (median reported 5% versus 50%) (p= 0.010) in comparison to men who had never used PrEP. It is encouraging that men having higher-risk sex had been accessing PrEP. However, further research is required to explore PrEP uptake, retention and adherence in this high-risk group.

The use of drugs in sexual settings among gay men (colloquially referred to as 'chemsex') was first observed in services supporting gay men in London in the late 2000s. A decade on and it now features as a policy issue in the UK Government's latest Drug Strategy, with several actions to support a health system response. However, reaching this point has been a slow and challenging process and much remains to be done to facilitate an environment in which evidence-based chemsex interventions can be delivered. With a view to informing the development of policies and services in other contexts, this case report examines the initiatives that have driven a response to chemsex and contributed to policy development in England and highlights remaining challenges to effective service provision.