Exogenous melatonin use, perceived safety, and adverse effects among medical university students in Syria: a cross-sectional study

Sleep disturbance is a major public health concern among university students, particularly in conflict-affected settings such as Syria where academic stressors are compounded by prolonged socioeconomic hardship. Exogenous melatonin is increasingly used as a sleep aid, yet data on its prevalence, patterns, and associated factors among Syrian medical students remain scarce. This cross-sectional study aimed to determine the prevalence, patterns, and associated factors of exogenous melatonin use among medical university students in Syria, with emphasis on reasons for use, timing relative to examinations, perceived effectiveness and safety, and self-reported adverse effects. A total of 647 medical university students across Syria completed an Arabic, self-administered online questionnaire during the 2025–2026 academic year. The survey assessed sociodemographic characteristics, lifestyle behaviors, patterns of melatonin use, attitudes toward safety and efficacy, and adverse effects. Descriptive statistics and chi-square tests were used to analyze the data on SPSS v27.0. The prevalence of exogenous melatonin use was 13.6% ( n = 88). Among users, the primary reason for use was insomnia (71.6%), followed by improving sleep quality (21.6%). Most users reported taking melatonin during examination periods (81.8% agreed/strongly agreed), whereas use outside examination periods was less common (45.4%). A large majority perceived improved sleep quality (87.5%) and considered melatonin safe (73.9%). Nearly 40% of users reported at least one adverse effect, with headache being the most common (60% of those affected), followed by dreams/nightmares (40%), mood changes (31.4%), and dizziness (25.7%); most adverse effects were mild to moderate. Working outside the university (χ 2 = 8.607, p = 0.003) and frequent electronic device use before sleep (χ 2 = 17.734, p < 0.001) were significantly associated with melatonin use. Exogenous melatonin use among Syrian medical students is commonly reported in the context of examination-related insomnia and academic stress. While generally perceived as safe and effective, a considerable proportion of users experience adverse effects most commonly headache and neuropsychiatric symptoms. These findings highlight the need for student-centered sleep-health education, pharmacist counseling, and university-based mental health interventions to promote safer self-medication practices in this vulnerable population.