RT Journal Article SR Electronic T1 S07.2 Chemsex and STI/HIV diagnoses among gay, bisexual and other men who have sex with men attending sexual health clinics JF Sexually Transmitted Infections JO Sex Transm Infect FD BMJ Publishing Group Ltd SP A15 OP A15 DO 10.1136/sextrans-2019-sti.41 VO 95 IS Suppl 1 A1 Aseel Hegazi YR 2019 UL http://sti.bmj.com/content/95/Suppl_1/A15.2.abstract AB Chemsex refers to the sexualised use of psychoactive substances in particular by gay, bisexual and other men who have sex with men (GBMSM). A socially constructed phenomenon, there is no agreed case definition for chemsex with substance use and social settings varying widely between settings. Substances commonly used for chemsex include methamphetamine, GHB/GBL (Gamma hydroxybutyrate/Gamma butyrolactone), mephedrone and other cathinones, cocaine, ketamine, and other amphetamines. The presentation will review published data on chemsex and in particular explore the relationship between chemsex and sexually transmitted infections including HIV. The talk will also highlight implications for wider health policy and current knowledge and research gaps.Disclosure No significant relationships.