ChemSex Support
56 Dean Street

What is chemsex?

ChemSex is a word invented on geo-sexual networking apps by gay men (and adopted by the gay men’s health sector) that defines a syndemic of specific behaviours associated with specific recreational drugs, and is particular to a specific, high risk population. 

Though the media spotlight may have distorted the term to define the use of any drugs in sexual contexts by any population, ChemSex actually refers to the use of any combination of drugs that includes crystal methamphetamine, mephedrone and/or GHB/GBL by Men who have Sex with Men (MSM) before or during sex. 

It is less of a traditional sex and drug issue; instead it’s related to the use of changing technologies, easy availability of certain recreational drugs via these technologies, and is adopted by a small, (international) but very sexually active group of men who are far more likely to contract HIV through this behaviour than their non-MSM counterparts (due to high prevalence within that population). 

ChemSex is also often associated with some cultural idiosyncrasies unique to gay cultures that may complicate sex for gay men. It is important that the health sector remains vigilant in providing care for anyone using drugs for sex, but also that a particular focus is given to gay and bisexual men using these drugs in this context as this represents a particular challenge to public health and communities, and some redesigning of the way in which care is delivered.

Drugs associated with ChemSex and their effects

Although drugs and alcohol have often been used in sexual contexts throughout history, crystal methamphetamine, mephedrone and GHB/GBL provide a particular sexually-disinhibiting “high”, which represents a different public health concern than that associated with other drugs more commonly used in the past. 

These three drugs have unfortunately become very common and readily available within gay “scenes” over the last decade, and their use has been accompanied by higher-risk sexual activity than has ever been observed or associated with any other kind of drug use. Users of these drugs can feel invulnerable to harm, supremely confident, dismissive of consequences, sexually adventurous, experience a heightened sense of pleasure, and can possess a stamina and endurance that may keep them awake for many days. When used in sexual contexts, this can translate into a reduced concern for safer sex practices and contact with a higher number of partners during a short, concentrated period of time. Unwanted side effects while under the influence can include aggression, paranoia, hallucinations/perceptions of persecution, overdose and more.

The role of geo-sexual networking Apps (eg, Grindr) in the rise of ChemSex

Geo-sexual networking apps have served a beneficial function in gay men’s lives in some ways, though there have also been some negative consequences. Sex for gay men is often associated with risk and danger; this is a consequence of an HIV epidemic that (in the UK) has particularly affected gay men. Many other gay men struggle with sex and intimacy having grown up struggling with a different sexual identity, cultural (or internalised) homophobia or a desire to fit in and avoid rejection. 

Apps were adopted very quickly by gay communities as a way to date and seek sex; yet communicating one’s sexual and emotional needs via the use of abbreviations, word counts and photo-shopped avatars can be very challenging for many people, and can often lead to unenjoyable sexual encounters. “Chems” have become a tool used by many to negotiate or overcome these challenges and are often commonly available via these technologies in some big cities that host large gay communities.

ChemSex prevalence

Global prevalence of ChemSex is not known, as it is a relatively new syndemic for researchers – many still struggle to define ChemSex, let alone quantify it. Anecdotal reports of varying concern have emerged from gay community organisations and sexual health services in the United States, Australia, Canada, Mexico, Australia, Asia and Europe. The UK, and in particular London, has had the most robust response to the trends, with 56 Dean Street becoming a global model for ChemSex support. There are enough reports and emerging data to prioritise ChemSex as a public health concern and to develop effective responses, and to do so, quickly, sensitively, and without moral judgments, even if robust evidence is lacking.  

ChemSex data from 56 Dean Street (a sexual health & HIV clinic in London, part of the Chelsea & Westminster hospital NHS foundation Trust.)

Approximately 3,000 gay men accessing 56 Dean Street services each month are using Chems (crystal methamphetamine, mephedrone and GHB/GBL). 56 Dean Street diagnose between 20 and 30 gay men who are regular Chem users with HIV each month. They also prevent between 200 and 300 gay men from potentially contracting HIV from ChemSex situations each month, by prescribing PEP (Post-Exposure Prophylaxis), a medicine which (if taken within 3 days of the sexual risk), will prevent the infection taking hold.  

More ChemSex-specific data from 56 Dean Street here.

Reducing the harmful effects of ChemSex

Clinicians in GUM/HIV services need to be alert to certain risks, and may want to ask the following questions;

  • Which drugs are being used (before or during sex)?
  • How are the drugs taken? (smoked, snorted, injected, taken orally or anally)
  • How frequently is this happening?
  • When did you last have sober sex?
  • How many partners might a typical ChemSex episode include?
  • How consistent is condom use during ChemSex episodes?
  • If HIV positive; are you on ARV treatment? Do you sometimes forget to take your medicine when on chems? (clinicians should be alert for Drug/Drug Interactions)
  • If HIV negative; how many previous PEP courses have you done? Are you aware of what seroconversion symptoms might be? Are you taking PrEP?
  • How many other STIs have you had in the last 6 months?
  • Are you aware of safer ChemSex  practices to avoid hepatitis C? (See link)
  • Are any of the drugs being used daily/consistently/dependently? (GHB/GBL being the urgent concern)

Most of 56 Dean Street's ChemSex patients do not come to the clinic seeking support for a drug problem or addiction issues; instead they are identifying issues around seeking sex and relationships, struggling with online and App use behaviours, issues around HIV fear and stigma, struggling in their pursuit of connection and community, and many other gay cultural idiosyncrasies that impact their sex and romantic lives. 

The best way to reduce the harms of ChemSex, is to develop a robust understanding of what we want our sex and romantic lives to be like, to set some goals and boundaries around that, and having the awareness and communication skills to pursue these goals/protect those boundaries. if we all enjoyed good sexual wellbeing, born of a cultural dialogue about the role sex and intimacy plays in our lives, then ChemSex related harms would be better avoided. It is important that sexual health clinics and gay community organisations provide services that go beyond simple testing and prescribing of medicine, which also support our patients and communities to develop good sexual and general wellbeing, including adapting to cultural changes that many may be struggling to adapt to.


Increasing availability/use of sexually-disinhibiting drugs[1], by a population of people that represent high HIV prevalence[+2], making use of technologies that facilitate easy pursuit of sexual partners[+3]... does indeed equal a public health concern that deserves a non-alarmist, but proportionate response. It is also a concern that deserves our compassion for a vulnerable group of people that are struggling with cultural changes associated with sex and relationships, and will certainly not benefit from further stigma or judgment, despite the sensationalist potential of these behaviours.

More ChemSex-specific resources, research, films & articles to be found here.

The above is the expert opinion of David Stuart

David Stuart is the Substance Use Lead, ChemSex clinics

Dean Street Wellbeing programme Manager

56 Dean Street, GUM/HIV

56 Dean Street is a sexual health and wellbeing centre in London’s Soho (part of the Chelsea and Westminster hospital NHS Foundation Trust).

13,000 people access its’ services each month.

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