Background:
     
     Due to widespread use of supplement among athletes, determining the prevalence and pattern of dietary supplement consumption and its moderators will be a road map for developing a strategic planning in the national level to achieve healthy lifestyle and avoid harmful nutritional approaches.
   

Methods:
     
     A systematic search of the electronic resources including Medline, PubMed, Scopus, Google Scholar and National Persian Databases including Magiran, SID, IranDoc and CIVILICA (between 1979 and November 2019 in Persian and English language) was accomplished. Inclusion criteria were (a) studies containing the prevalence rate of dietary supplement consumption, specifically (b) studies were conducted in athletes. Finally, 32 articles were included.
   

Results:
     
     The prevalence rate of supplement use in overall Iranian athletic population was 64.8% (95% CI, 55.8%-73.8%) with significant heterogeneity (I² = 99.7%, P < 0.001). The prevalence rate was reported to be higher in male athletes, athletes aged 25 and older and elite athletes (P < 0.05). The most prevalent source of information about supplement use among athletes were trainers, followed by physicians, friends-teammates and dietitians.
   

Conclusions:
     
     According to the high prevalence of supplement consumption among Iranian athletes, policy making for educational programs is mandated. Trainers are the most popular source to provide information about supplements and educational programs should be conducted for this target population.