Self-medication among medical students: prevalence, patterns and factors associated with frequent self-medication

Self-medication is a common practice, particularly among medical students, and may reflect both self-care strategies and risk behaviours when performed inappropriately. In Portugal, data on this phenomenon among medical students remain limited, despite its potential clinical and educational relevance. To assess the pattern of self-medication and identify factors associated with self-medication among medical students. A cross-sectional study was conducted using a self-administered electronic questionnaire among medical students at the University of Porto. Self-medication was defined as the use of medication without a medical prescription during the previous 12 months. Sociodemographic variables, self-medication patterns, motivations, sources of guidance, knowledge, and attitudes were analysed. Descriptive, bivariate, and multivariable logistic regression analyses were performed to identify factors associated with frequent self-medication. A total of 247 medical students participated in the study, corresponding to a response rate of 14.5% among approximately 1,700 eligible students. The prevalence of self-medication was 89.9%, with 34.0% of students reporting frequent use. Analgesics and anti-inflammatory drugs were the most commonly used medications, followed by vitamins, dietary supplements, and natural products. Sedatives, tranquillisers, and antibiotics were reported less frequently. Physical symptoms, particularly pain, fever, and cough, were the main triggers for self-medication, although psychological and academic-related symptoms were also reported. In the multivariable analysis, acceptance of previously prescribed medication reuse (OR = 2.230; 95% CI: 1.058–4.701) and the belief that self-medication is the best option for one’s health (OR = 3.295; 95% CI: 1.640–6.620) were independently associated with frequent self-medication. Academic year (4th–6th years) showed a borderline association with frequent self-medication (OR = 2.033; 95% CI: 0.999–4.138; p = 0.050). Self-medication was highly prevalent among medical students, with frequent use reported by approximately one-third of participants. Acceptance of medication reuse and the belief that self-medication benefits personal health were independently associated with frequent self-medication. These findings suggest that attitudes towards medication use may play an important role in self-medication behaviour and highlight the need for educational interventions addressing behavioural determinants to promote safer and more rational medication use among future physicians.