Gay and bisexual men with problematic chemsex are a diverse group with significant sexual and psycho-social risks

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Men who have sex with men (MSM) seeking support because of chemsex are a diverse group and have a range of behaviours that pose a high risk to their physical health and psycho-social wellbeing, according to research published in Sexually Transmitted Infections. Analysing the needs of gay and bisexual men seeking support from Antidote (a specialist service supporting LGBT individuals with drug and/or alcohol issues in London), the study showed that MSM engaging in chemsex had a high prevalence of HIV (47%), that many were current or past injectors and that thoughts of suicide were common. But use of specific drugs and their associated health outcomes differed according to several demographic factors, including age, race and HIV infection status.

The authors believe their findings have important implications for the design of services to support MSM with chemsex issues.

“This analysis has shown…that Antidote’s chemsex-related drug use MSM population is one at high risk,” write the authors. “Services should be provided under a model of integrated care, whether providing services under a single roof, or through establishing effective, rapid care referral pathways between services.”



The use of recreational drugs such as mephedrone, GHB/GBL and crystal meth before or during sex.


The transition period from infection with HIV to the detectable presence of HIV antibodies in the blood. When seroconversion occurs (usually within a few weeks of infection), the result of an HIV antibody test changes from HIV negative to HIV positive. Seroconversion may be accompanied with flu-like symptoms.



A healthcare professional’s recommendation that a person sees another medical specialist or service.

post-exposure prophylaxis (PEP)

A month-long course of antiretroviral medicines taken after exposure or possible exposure to HIV, to reduce the risk of acquiring HIV.

heterogeneous or heterogeneity

Diverse in character or content. For example, the ‘heterogeneity’ of clinical trials means that they, and their results, are so diverse that comparisons or firm conclusions are difficult.

Chemsex has been identified as a major public health concern for gay men. But there are few data on the characteristics of men seeking support for problematic chemsex and this information is needed to shape appropriate and effective services.

Investigators from Antidote therefore designed a cross-sectional study involving approximately 2300 MSM who accessed their services between 2012 and 2018.  At the time of referral, individuals were asked to provide information about the drug/drugs which they were experiencing problems with, their HIV and HCV infection status and also about their drug-use and sexual risk behaviours. Demographic information was also obtained.

The investigators compared the characteristics of MSM seeking support for chemsex (use of mephedrone, methamphetamine, GBH/GBL) and individuals who were having problems with the use of other drugs (for example, cocaine, cannabis, alcohol).

Individuals reporting chemsex were then analysed according to which drug they used. A second analysis examined the characteristics and risk behaviours of HIV-positive men with problematic chemsex.

Half of HIV-positive individuals reporting chemsex attributed their HIV seroconversion to chemsex.

Overall, 93% of participants identified a primary drug of concern, of whom 88% were seeking support for a chemsex drug. Approximately a quarter identified one drug of concern, a third reported two drugs of concerns and almost half said they were concerned about the use of three of more drugs.

Men presenting for chemsex drugs were over three times more likely than those presenting for non-chemsex drugs to report problems with more than one drug (aPR = 3.37; 95% CI, 2.88-3.94, p < 0.0005).

Mephedrone was the most frequently reported drug (71%), followed by GHB/GBL (69%) and methamphetamine (64%). Among the non-chemsex service users, alcohol (57%), cocaine (42%) and cannabis (21%) were the most frequently cited substances.

Almost all the men identified as gay (95%), two-thirds were British and 84% were white. Most were employed (68%). The median age was 35 years.

Being younger (under 45 years), identifying as gay and black, Asian and minority ethnic (BAME) origin were all associated with chemsex drugs.

The majority of participants were HIV-negative (53%), of whom a third had used post-exposure prophylaxis in the previous year. Over half were current or past injecting drug users (53%) and most reported hazardous alcohol consumption (59%). Two-thirds reported a minimum of six sexual partners in the previous 90 days. Thoughts of suicide were reported by 15% of individuals.

Of the current injectors, 40% said they shared injecting equipment. Prevalence of HCV infection was 9%.

Chemsex was associated with being HIV-positive, intravenous drug use, using PEP and higher numbers of sexual partners.

Further analysis of men seeking support for chemsex showed that this was a highly diverse group and that demographic characteristics and risk behaviours differed according to the drug of concern.

For instance, being younger and employed was associated with problematic mephedrone use (p < 0.0005), while being older and BAME was associated with use of methamphetamine (p < 0.0005).

Individuals having problems with mephedrone were less likely to be HIV- or HCV-positive, to inject drugs or to report suicidal thoughts. However, mephedrone use was associated with problematic alcohol consumption. Selecting methamphetamine was associated with all the above characteristics except problematic alcohol use.

Individuals selecting GBH/GBL as the primary drug of concern were less likely to inject drugs or be HIV-positive, but use of this drug was associated with suicidal ideation.

Subgroup analysis of the HIV-positive individuals reporting chemsex showed that 47% attributed their HIV seroconversion to chemsex. Half said their drug use escalated after their diagnosis, with a third saying they initiated use of drugs following diagnosis with HIV. Most were on antiretroviral therapy (85%), with over half of these individuals agreeing that chemsex had a negative impact on treatment adherence. HIV/HCV coinfection was present in 11% of individuals.

“We show that the needs of chemsex-related drug using MSM are heterogeneous and service responses should reflect this,” advise the authors. “Warning a 25-year-old HIV– man who uses exclusively mephedrone and does not identify with HIV+ methamphetamine injectors on the risks of sharing injecting equipment does not ‘make every contact count’, and indeed may discourage future engagement with services.”


Stevens O et al. Chemsex-related drug use and its association with health outcomes in men who have sex with men: a cross-sectional analysis of Antidote clinic service data. Sex Transm Infect: o0-1-7, doi.10.1136/sextrans-2019-054040.