Abstract
            Introduction: Anemia is a common complication of chronic kidney disease (CKD) due  to the insufficient production of erythropoietin by the kidneys. The administration of  erythropoietin is one of the most common methods for the treatment of patients with anemia.  
  Objectives: This study aimed to investigate the effect of the administration of synthetic  erythropoietin on hemoglobin levels in dialysis patients using a systematic review and meta-analysis.  
  Methods: In order to identify the related studies, the international databases of Web of  Science, PubMed, Scopus, and Embase were searched from 2015 to 2020 using standard and  valid keywords. The data were analyzed using STATA software (version 14), and a p-value of  less than 0.05 was considered statistically significant.  
  Results: In 12 reviewed articles with a sample size of 4,060 individuals, the standard effect  size of the effect of synthetic erythropoietin on Hb in dialysis patients was reported as 2.08  (95% CI: 1.53-2.63), which was statistically significant; however, erythropoietin biosimilars  did not show similar results.  
  Conclusion: The administration of erythropoietin to hemodialysis patients increases Hb  levels by more than 2 units.