Chemsex: Venereological Consequences, Psychiatric and Somatic Complications, and Potential Intervention Strategies

Background/Objectives: Chemsex is defined as the intentional use of psychoactive substances to enhance or prolong sexual activity, predominantly observed among men who have sex with men. It has emerged as a notable behavioral and public health concern due to its association with high-risk sexual practices, psychiatric morbidity, and somatic complications. Despite increasing recognition, global prevalence estimates vary widely (3–52.5%) due to differences in study populations and methodology. Commonly used substances include synthetic cathinones, amphetamines/methamphetamines, MDMA, GHB/GBL, ketamine, alkyl nitrites, and PDE-5 inhibitors. Methods: A narrative review was conducted using PubMed through 11 December 2025. Search terms combined chemsex-related terminology, substance names, and health outcomes. Recent English-language publications (2020–2025) were prioritized. Evidence was synthesized thematically across epidemiology, health complications, motivations, and interventions. Results: Chemsex is strongly associated with unprotected sex, multipartner encounters, and prolonged intercourse, leading to significantly increased rates of HIV, syphilis, gonorrhoea, and chlamydia. Psychiatric complications include depression, anxiety, compulsive sexual behavior, and psychosis, with higher risks in individuals engaging in slamming or polysubstance use. Somatic complications vary by substance and include cardiovascular disease, hyponatremia, rhabdomyolysis, ulcerative cystitis, methemoglobinemia, and overdose. Motivational factors extend beyond sexual enhancement and include minority stress, internalized and externalized stigma, and maladaptive coping mechanisms. Integrated interventions combining harm reduction, cognitive–behavioral therapy, peer-led services, and pharmacotherapy, alongside digital health tools to support PrEP adherence and risk reduction, show promise in mitigating these harms. Conclusions: Chemsex represents a complex interplay of biological, psychological, and sociocultural factors that contribute to elevated STI risk and psychiatric and somatic morbidity. Addressing chemsex requires destigmatized, multidisciplinary approaches that integrate behavioral, pharmacological, and community-based interventions. Digital health innovations can further enhance engagement, risk reduction, and access to timely care.