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Chemsex

Substance use: chemsex

The word chemsex was first used in 2001 and describes using methamphetamine and/or synthetic cathinones (3-MMC or 4-MMC) and/or GHB or GBL (gamma-hydroxybutyrate/gamma-butyrolactone) specifically for reducing inhibitions and enhancing sexual pleasure by men who have sex with men (MSM).

The definition of drugs included in chemsex is not clearly defined and shows heterogeneity between study publication.

More generally speaking, chemsex behaviors are described as the use of specific drugs before or during planned sex to facilitate, initiate, prolong, sustain and intensify the encounter.

The prevalence of chemsex in Europe is 16% [11-21%] among MSM. The most frequent risky sexual behaviour associated with chemsex practice was unprotected sex with a high number of partners. The log risk ratio of STIs was 0.86.

Medical consequences of chemsex use

For stimulants (methamphetamine and synthetic cathinones): difficulty sleeping, loss of appetite and weight loss, dehydration and reduced resistance to infection, jaw clenching, headaches and muscle pain, mood swings, anxiety, depression, agitation, mania, panic episodes, tremors, irregular heartbeat and shortness of breath, difficulty concentrating and remembering things, paranoia, aggressive and violent behavior, psychosis after repeated use of high doses, permanent damage to brain cells, liver damage, brain haemorrhage and sudden death from cardiovascular acute conditions.

For sedatives (GHB/GBL): drowsiness, dizziness and confusion, difficulty concentrating and remembering things, nausea, headaches and unsteady gait, sleeping problems, anxiety and depression, tolerance and dependence after a short period of use, severe withdrawal symptoms, overdose and death if used with alcohol, opioids or other depressant drugs.

Chemsex use in people with HIV

Numerous studies have identified an association between the use of drugs in sexual contexts (chemsex) and HIV among gay, bisexual, and other men who have sex with men (GBMSM), although whether a causal relationship exists is contentious. An intricate relationship exists between chemsex, HIV treatment and prevention, harm reduction, and the provision of community-grounded health services. Furthermore, potential harms exist beyond HIV, such as intoxication and overdose. Community-engaged responses to chemsex involve social and cultural strategies of harm reduction and sexual health promotion before, during, and after a chemsex session

Screening for chemsex use

Who? How to screen? How to diagnose chemsex use disorder?

Recommend screening people with HIV at least once a year (in view of the high prevalence of chemsex use)

Populations at particularly high risk

Ask: Do you ever consume drugs before or during planned sex to facilitate, initiate, prolong, sustain and intensify the encounter?

If yes: explore with the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST):

  1. In the past three months, how often have you used chemsex? (Score)
    Never (0)
    Once or twice (2)
    Monthly (3)
    Weekly (4)
    Daily or almost daily (6)
  2. During the past three months, how often have you had a strong desire or urge to use chemsex? (Score)
    Never (0)
    Once or twice (3)
    Monthly (4)
    Weekly (5)
    Daily or almost daily (6)
  3. During the past three months, how often has your use of chemsex led to health, social, legal or financial problems? (Score)
    Never (0)
    Once or twice (4)
    Monthly (5)
    Weekly (6)
    Daily or almost daily (7)
  4. During the past three months, how often have you failed to do what was normally expected of you because of your use of chemsex?
    Never (0)
    Less than monthly (5)
    Monthly (6)
    Weekly (7)
    Daily or almost daily (8)
  5. Has a friend or relative or anyone else ever expressed concern about your use of chemsex?
    No, never (0)
    Yes, in the past 3 months (6)
    Yes, but not in the past 3 months (3)
  6. Have you ever tried to cut down on using chemsex but failed?
    No, never (0)
    Yes, in the past 3 months (6)
    Yes, but not in the past 3 months (3)

    Add up the scores received for questions 1 through 6 inclusive.
    Do not include the results from question 7 in this score.
    The type of intervention is determined by the score of the risk level:
    0 – 3:
    lower risk - No intervention
    4 – 26:
    moderate risk - Receive brief intervention (***)
    27+:
    high risk - More intensive treatment / referral to addiction unit

  7. Have you ever used any drug by injection (non-medical use only)?
    No, never
    Yes, in the past 3 months
    Yes, but not in the past 3 months

People who have injected drugs in the last 3 months should be asked about their pattern of injecting during this period, to determine their risk levels and the best course of intervention.

Pattern of injecting and recommended intervention guidelines:
If injecting pattern of 4 days per month on average over the last 3 months or less, then start brief intervention (***)

If injecting pattern of more than 4 days per month on average over the last 3 months, then refer to the Addiction Unit.

Explore whether three or more of the following characteristics appear simultaneously, or have been present in the last 12 months (ICD-10 criteria)

  1. Intense desire or compulsion to consume
  2. Decreased ability to control:
    • the onset of consumption
    • ending intake and the amount
  3. Withdrawal symptomatology
  4. Tolerance or neuroadaptation
  5. Progressive abandonment of activities
  6. Persistence in consumption despite the harmful consequences

Does the person meet ICD-10 criteria?
• NO: risky / harmful consumption
• YES: substance use dependence - refer the individual to the addiction unit

For risky consumption or where addiction unit is not available, initiate brief intervention or motivational interviewing


The Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) was developed for the World Health Organization (WHO) by an international group of researchers and clinicians as a technical tool to assist with early identification of substance use related health risks and substance use disorders in primary health care, general medical care and other settings
See www.who.int/publications/i/item/978924159938-2

Brief intervention (***) 

The aim of the brief intervention is to help the client understand that their substance use is putting them at risk which may serve as a motivation for them to reduce or cease their substance use. Brief interventions should be personalized and offered in a supportive, non judgmental manner;
1. Asking clients if they are interested in seeing their questionnaire scores;
2. Providing personalised feedback to clients about their scores on the ASSIST questionnaire;
3. Giving advice about how to reduce risk associated with substance use;
4. Allowing clients to take ultimate responsibility for their choices;
5. Asking clients how concerned they are by their scores;
6. Weighing up the good things about using the substance against the less good things about using the substance;
7. Summarize and reflect on clients’ statements about their substance use with emphasis on the ‘less good things’;
8. Asking clients how concerned they are by the ‘less good things’;
9. Giving clients take-home materials to bolster the brief intervention

Humeniuk RE, Henry-Edwards S, Ali RL et al. The ASSIST-linked brief intervention for hazardous and harmful substance use: manual for use in primary care (2010). Geneva, World Health Organization