Sport Supplement Use in 14–18-Year-Old Adolescents: A Single-Group Pre–Post Social Media Educational Intervention Study

BACKGROUND: The use of sports supplements among adolescents is rising globally, driven by fitness trends and social media influence, yet knowledge gaps persist. This study aimed to assess supplement usage patterns, knowledge, attitudes, information sources, and the impact of a social media educational intervention among Serbian secondary school students. METHODS: A single-group pre-post educational intervention study was conducted in secondary school students (aged 14-18) in Vojvodina, Serbia. A 21-question anonymous questionnaire was distributed to 1000 students along with parental informed consent forms. Pre-intervention survey assessed sociodemographics, physical activity and social media habits, supplement use information sources, and awareness of risks and banned substances. Based on the initial findings, an educational campaign delivered 56 short videos (≈70 s each) on Instagram and TikTok covering most frequently used supplements (e.g., creatine, proteins, caffeine, energy drinks). After, the intervention survey was repeated. The data were analyzed using the McNemar-Bowker test of symmetry. RESULTS: In this study, 65% of Serbian secondary school adolescents reported being physically active, engaging predominantly in gym workouts and team sports. The majority of participants initiate dietary supplement use independently, without consulting healthcare professionals or adults. The most commonly used supplements were vitamins and minerals, while energy drinks ranked notably high. Social media intervention had a limited impact due to its short duration; however, certain changes were detected. CONCLUSIONS: Serbian adolescents frequently use sports supplements without adequate professional guidance. Long-term TikTok/Instagram interventions could be used in the future in order to influence behaviors and improve knowledge about sport supplement use.