Blomquist PB, Mohammed H, Mikhail A, et al. - As sexual behaviors with higher sexually transmitted infection (STI) risk are observed in association with chemsex, the use of select psychoactive drugs to enhance sexual experience, typically among men who have sex with men (MSM), researchers sought to understand patterns of chemsex among MSM as well as the characteristics and sexual health service engagement of chemsex participants considering their importance for developing interventions. From May 2016 to May 2017, completion of an online survey was done by 3,933 MSM, recruited in sexual health clinics (SHCs) in England (n = 421) and via four social networking/dating apps (n = 3,512). Ten percent of respondents reported Chemsex in the past year; 19% of SHC-recruited and 9% of app-recruited. This indicate engagement of one in 10 MSM recruited through community and clinical settings across England in chemsex in the past year. Those that did appear to be at higher STI risk but engaged more actively with sexual health services. This emphasizes the requirement and opportunity for chemsex-related services in SHCs and strong referral pathways to drug treatment services.