Background Combining drugs and sex has been associated with an increased risk for sexually transmitted infections. Recently, there has been considerable interest in drug use during sex among men who have sex with men (‘chemsex’) in STI clinical practice, but data in swingers are lacking. Our study assessed the types of drugs used, and associated sexual risk behaviour, in swingers who are either bisexual male, heterosexual male or female.

Methods In 2018, 1005 participants completed an online questionnaire that was advertised at Dutch swinger-websites. Inclusion criteria were: swinging (heterosexual couples having sex with others or singles having sex with other heterosexual couples) and being aged ≥18 years. Drug use during sex was assessed and compared between heterosexual male, bisexual male, and female swingers using χ²-tests. Multivariable logistic regression analysis was used to evaluate possible factors (sociodemographics, alcohol, and condomless sex with swing partners) associated with drug use.

Results Drug use while swinging was reported by 44% (443/1005); 51% in women, 44% in bisexual men, and 39% in heterosexual men (p=0.007). Among drug-using swingers, XTC (92%;409/443), GHB (76%;338/443), and laughing gas (69%;304/443) were mostly used; 69% (305/443) used ≥4 different drugs (polydrug use). Condomless vaginal sex was reported by 46% in drug-using swingers (vs. 35% in non-drug-using swingers;p<0.001) and condomless anal sex by 30% in drug-using swingers (vs. 21% in non-drug-using swingers;p=0.012). Being a woman (aOR:2.10; 95%CI:1.36–3.09) and condomless vaginal sex (aOR:1.71; 95%CI:1.24–2.35) were independently associated with drug use.

Conclusion This study among a large group of swingers shows that drug use and polydrug use during sex are prevalent among both male and female swingers in the Netherlands, indicating that ‘chemsex’ is not only common among MSM. The association between drug use and sexual risk behaviour suggests that it might be useful to tailor STI prevention strategies, developed for MSM engaging in chemsex, for swingers.

Disclosure No significant relationships.