The harmful effects of taking selegiline for a long period of time vary from person to person, the performance of each patient is not exactly the same, or there may be no obvious harmful effects. Common adverse reactions include allergy, elevated liver enzymes, upper respiratory tract infection, pancreatitis, etc. Regular physical examination should be performed, and the medication can be adjusted or discontinued under the guidance of a doctor if obvious discomfort occurs. Selegiline belongs to the class of dipeptidyl peptidase-IV inhibitor hypoglycemic drugs, which can promote insulin secretion by increasing the level of GLP-1 in the body. It is mainly used for the treatment of type 2 diabetes, and can be used as a single drug or in combination with metformin, sulfonylureas, insulin and other drugs. The harmful effects of long-term selegiline vary from person to person, and should be assessed comprehensively according to one’s own clinical symptoms, laboratory test results, the performance of each patient is not exactly the same, or there may be no obvious harmful effects. Common adverse reactions to selegiline include allergy, elevated liver enzymes, upper respiratory tract infections, pancreatitis, etc. It is contraindicated in patients who are allergic to any of the components in the product, or who have diabetic ketoacidosis. The drug should be used in strict compliance with the doctor’s instructions, regular medical checkups, and should not be used, adjusted or discontinued on its own.