Chemsex refers to the intentional use of psychoactive substances to enhance sexual expériences. It often involves prolonged sexual sessions, multiple partners, and the use of drugs such as GHB, synthetic cathinones, and erectile dysfunction medications. Prevalence estimates vary widely across studies, ranging from 9 to 21% in Europe, reflecting heterogeneity in definitions and populations studied. This practice can be associated to serious health risks, including substance addiction, psychiatric disorders, and increased rates of sexually transmitted infections (STIs), notably HIV and hepatitis C. Intravenous drug use during sex (“slamming”) carries particularly high risks. Despite its initial emergence in men who have sex with men (MSM) communities, chemsex is also reported among heterosexual and transgender populations. Effective responses require non-judgmental, multidisciplinary support, combining harm reduction, mental health care, and STI prevention. Healthcare professionals must be trained to recognize and address chemsex-related issues. Further research is needed to better define the phenomenon and inform public health strategies. This article provides a brief review of the characteristics, epidemiology, and potential addictive, infectious, and psychological consequences of chemsex.