Background Chemsex, the use of drugs (including crystal methamphetamine, mephedrone and/or GHB/GBL) to enhance sex, is practiced by men who have sex with men (MSM) and has risen in the last decade. Non-consensual sex is hypothesized to occur frequently under the influence of chemsex, however has not been investigated much. In this study we aimed to quantify chemsex use in the Amsterdam area and to establish whether non-consensual sex is associated with chemsex engagement.

Methods During the Amsterdam Pride in 2016 and 2018, Amsterdam-located users of a gay dating application were asked about chemsex behavior in the previous 6 months and non-consensual sexual experiences in the past 5 years (the latter in 2018). Non-consensual sex was defined as ‘non-consensual sex or experience (e.g. filmed/photographed without consent)’. X² test for independence was used for statistical analyses.

Results A total of 1833 (2016) and 756 (2018) participants were included of which 28.3% and 27.8% engaged in chemsex (p=0.81). In 2018 the occurrence of non-consensual sex was high, but not significantly different among the chemsex (20.4%) and non-chemsex (16.5%) group (p=0.22). Yet, among those with chemsex being filmed/photographed without consent, taking drugs against ones will and passing out, were reported more often than among those without chemsex (p<0.05). The intensity of emotional distress related to non-consensual sex was not significantly different between the chemsex and non-chemsex group (p=0.63).

Conclusion The proportion of MSM in Amsterdam who engage in chemsex is high but stable over 2016–2018. The proportion of MSM experiencing non-consensual sex is also high, but not associated with chemsex engagement, nor is the intensity of emotional distress related to chemsex. Nonetheless, the type of non-consensual experience differs between the chemsex and the non-chemsex group. Sexual healthcare professionals need to address chemsex use and non-consensual sex during consultations involving MSM and refer men if deemed necessary.

Disclosure No significant relationships.