Peptides hormones from the amino acids by peptide bonds connected into the smallest peptide hormone may be composed of three amino acids, such as thyrotropin releasing hormone (TRH). Most peptide hormones can be made up of more than ten, dozens or even hundreds and hundreds of amino acids. The main secretory organs of the peptide hormone are the hypothalamus and the pituitary gland. Peptide hormones are found in other organs, and most of them are in the study stage. Its role is to promote growth and development of human body by stimulating adrenal cortex growth and erythrocyte production. Large intake will reduce its endocrine level, damage its health, and may cause cardiovascular disease, diabetes and so on. Similarly, the abuse of peptide hormones also forms a strong psychological dependence. EPO is a peptide hormone secreted by human kidney. It can increase the amount of erythrocytes generated by bone marrow, increase the content of hemoglobin and increase the capacity of oxygen and oxygen supply in blood. It is a drug for the treatment of renal anemia in clinic. Because it can significantly improve aerobic exercise time, some sports events and athletes have favored it. It has obvious effect on improving endurance events. It is said that the maximum increase of 15% is achieved. Another reason for EPO's preference for athletes is that EPO detection technology is not in international standard. However, after 2000, the detection technology of EPO has gradually improved and the situation has changed.
Because of a lot of abuse, EPO has killed 24 cyclists over the past 20 years. This is because EPO has increased the number of red blood cells in the blood, making blood thicker and slower blood flow, causing hypertension, resulting in tissue hypoxia, coagulation acceleration, and even leading to venous thrombosis, myocardial infarction, pulmonary embolism or cerebral infarction, resulting in death.