Chemsex and sexual risk behavior among MSM on PrEP in Stockholm, Sweden
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Updated: Sep 9, 2025

Assessment of Sexual Behavior of Male Mice
Published on: March 5, 2020
Rost Elin1, Westergren Victor1, Luksha Yauheni1
1Department of Infectious Diseases/Venhälsan, Södersjukhuset, Stockholm, Sweden.
Background:
Chemsex, typically defined as the use of specific psychoactive substances to enhance sexual experiences, has been linked to increased sexual health risks among men who have sex with men (MSM). This study examines frequency of chemsex use and associations between chemsex, risk-taking, and sexual practices among MSM on pre-exposure prophylaxis against HIV (PrEP) attending Sweden's largest sexual health clinic.
Methods:
A survey among MSM on PrEP (n = 290) mapped demographics, sexualized drug use, sexual practices, and alcohol use at Venhälsan, (South General Hospital), Stockholm, Sweden.
Results:
18 % engaged in chemsex at least once in the past year and 49 % of respondents using chemsex reported high-risk alcohol use or alcohol dependence and 13 % classified as dependent. Most individuals on PrEP practiced unprotected sex, 42 % used condoms as passive/bottom, only 31 % as active/top. Chemsex tripled the odds of not using a condom at least 50 % of the time: adjusted for age, education, AUDIT, and being born in Sweden. Participants using chemsex were 3 times more likely, to have more than 14 temporary partners (past year) and were twice as likely to engage in group sex (82 %) compared to those not using chemsex (40 %).
Conclusions:
Chemsex was associated with a threefold increased risk of condomless sex and showed a significant link to alcohol dependency. While PrEP offers effective protection against HIV infection, it does not prevent sexually transmitted infections. Health professionals and social workers should identify MSM who engage in chemsex and tailor interventions to address their specific needs.
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