Byzantium refers to Acarbose, Metformin and Acarbose are both diabetic medications, the side effects of Metformin and Acarbose cannot be compared in size, both have certain side effects. Metformin is absorbed through the stomach and intestines, long-term application of gastrointestinal reactions, such as nausea, vomiting, bloating, diarrhea and so on. It also reduces intestinal absorption of vitamin B12, leading to megaloblastic anemia. In addition, metformin can cause lactic acidosis. It is contraindicated in severe renal failure, severe infections, shock, acute metabolic acidosis, and hypersensitivity to metformin. Acarbose is decomposed and absorbed slowly in the small intestine, long-term application of some patients will experience increased gas, hyperactive bowel sounds, abdominal distension and other symptoms. Some individual patients will have skin allergic reactions such as rash and erythema, and also liver function impairment with obvious jaundice. Inflammatory bowel disease, severe renal impairment, severe liver disease, diabetic ketoacidosis, and hypersensitivity to acarbose are contraindicated. Metformin and acarbose, need to be rationally applied under the guidance of a doctor, if discomfort occurs, please consult a doctor for diagnosis.