Garlic, as a food, provides nutrition only and has no curative effect on mouth ulcers. Mouth ulcers should be treated properly when they occur. Mouth ulcers can be treated with topical medications, such as Triamcinolone acetonide oral ointment, dexamethasone acetate paste tablets, and compound borax gargle solution. 1. Tretinoin oral ointment: the main ingredient is tretinoin, which has anti-inflammatory and analgesic effects. 2. Dexamethasone acetate paste tablets: containing dexamethasone acetate, vitamin B2, etc., with anti-inflammatory and analgesic effects. 3. Compound Borax Gargle: containing borax, sodium bicarbonate, liquefied phenol, etc. It can dissolve corrupt tissues and has antibacterial, antiseptic and disinfectant effects. All of the above medicines should be used under the guidance of a doctor, and it is recommended to visit a regular medical institution to receive professional treatment.