Diabetes is known as the “undead cancer”, which means that it is not life-threatening as long as you control your sugar properly and avoid complications. However, diabetes is a lifelong disease that requires long-term medication, so it is important to choose a sugar control drug that is suitable for you and has fewer side effects. Metformin is a kind of metformin oral hypoglycemic drug, it is one of the most widely used hypoglycemic drugs in the world, the drug has the advantages of high safety, less side effects and low price, it is the drug of choice for the treatment of diabetes at present. At the same time metformin not only has reliable hypoglycemic effect and lower glycosylated hemoglobin, but also has cardiovascular protective effect, which can reduce the risk of cardiovascular disease complicated by diabetes. There are a lot of patients worry that long-term metformin will cause some damage to the liver, not knowing that long-term hyperglycemia or too much blood sugar fluctuation will damage liver and kidney function far more than the damage of metformin on liver and kidney function. In fact, long-term eating metformin for patients with normal liver function is no adverse effects. The basis is as follows: 1, metformin is different from most drugs is its structural stability, its absorption through the gastrointestinal tract into the circulation, almost not combined with plasma albumin, and does not go through the liver metabolism, do not compete with liver P450 enzymes, in the body is not degraded, but directly on the liver and muscle, reduce hepatic gluconeogenesis, increase gluconeogenesis. It has a plasma half-life of 1.7-4.5 hours and is 90% cleared within 12 hours. 2, Metformin in the body will act directly on the body cells, directly through the kidneys in the urine in its original form, in 24 hours, Metformin can be excreted more than 90%, therefore, the kidneys are the main way of Metformin excretion, the onset and excretion of Metformin do not need to go through the liver. Therefore, there is no adverse effect on the liver when metformin is taken for a long time. If abnormal liver function occurs during metformin administration, the effects of other drugs or the body’s own pathology should be considered first.