Erythropoietin (EPO) has been considered in several studies as a significant factor in the development of erythroid cells. EPO's critical function is managing red blood cell production; this feature makes it a vital factor in cell stability. In the absence of erythropoietin, red blood cell production stops. This crucial role has led to great approaches in physiological and cellular research related to erythropoietin. Over-stimulation of the bone marrow and high erythropoietin production can increase blood pressure and thrombosis. Fortunately, a modified version of EPO called Carbamyl Erythropoietin (CEPO) has tissue-protective properties but with non-erythropoietic effects. CEPO is a derivative of EPO that results in an alpha-amino derivative group with less biological hematopoiesis than EPO. In neurological and renal diseases, carbamyl erythropoietin (CEPO) has been shown to play a better role than EPO. In this study, the effects of EPO and CEPO on diseases and their role in treatment have been reviewed.