Selegiline and saxagliptin are not better, both belong to the DPP-4 inhibitor class of hypoglycemic drugs, each has its own characteristics, in terms of half-life, dosage, drug interactions and other aspects are different. 1. Different half-life and dosage: selegiline has a half-life of 12 hours and can be taken once a day at a dosage of 100mg; saxagliptin has a half-life of only 2.5 hours, but because of the covalent bonding with DPP-4, the binding and dissociation speed is slow, so although the half-life is short, the hypoglycemic effect can be sustained for 24 hours, and it can still be taken once a day at a dosage of 5mg. The dosage is 5mg. 2. Drug interactions are different: selegiline is usually excreted in its original form, and the interaction with other drugs is small; saxagliptin needs to be metabolized by the liver and excreted, and if it is used together with ketoconazole, clarithromycin, etc., the dose should be halved. Selegiline and saxagliptin should be applied under the guidance of a doctor and should not be taken on their own.