Selegiline does not have the so-called “most serious side effects”, the severity of side effects after the use of selegiline is related to the patient’s own situation, there are individual differences, common side effects include allergies, elevated liver enzymes, upper respiratory tract infections, pancreatitis and so on. Selegiline belongs to the class of dipeptidyl peptidase-IV inhibitor hypoglycemic drugs, which can increase the level of GLP-1 in the body to achieve the effect of promoting insulin secretion. It is mainly used for the treatment of type 2 diabetes mellitus, and can be used as a single drug or in combination with metformin, sulfonylureas, insulin and other drugs. Common adverse reactions to selegiline include allergy, elevated liver enzymes, upper respiratory tract infection, pancreatitis, nasopharyngitis, constipation, vomiting, headache, arthralgia, myalgia, limb pain, back pain and so on. The possible side effects and their severity may not be exactly the same in different patients taking the drug. It is contraindicated for patients who are allergic to any of the ingredients in this product, diabetic ketoacidosis, etc. Selegiline is a prescription drug and should be used under the supervision of a doctor to avoid delaying the condition or causing adverse reactions. In case of discomfort, please seek medical advice promptly.