At present, there is no oral insulin tablet. Since insulin is a protein, it is easily destroyed by enzymes in the gastrointestinal tract after oral administration and cannot be absorbed, so it cannot play a role in lowering blood sugar. According to the time of insulin action, insulin preparations can be divided into short-acting, fast-acting, medium-acting, long-acting and premixed insulins. According to the source, they can be divided into animal insulins, human insulins, and insulin analogues. The choice of insulin for glucose-lowering treatment must be made under the guidance of a professional endocrinologist and according to your blood sugar, pancreatic islet function, and physical condition. Some people may have insulin allergy, so they can change the insulin type or choose oral hypoglycemic drugs.