Ranitidine has no therapeutic effect on mouth ulcers and is generally used to treat stomach pain and acid reflux caused by excess stomach acid. Oral ulcers are generally treated by local medications, such as anti-inflammatory drugs, glucocorticoid drugs, etc., as follows. 1. Ranitidine: the main ingredient is Ranitidine, which is used to relieve stomach pain, heartburn and acid reflux caused by hyperacidity. it is prohibited for children under 8 years old, pregnant women and lactating women. Common adverse reactions include nausea, rash, and fatigue. Ranitidine has no therapeutic effect on mouth ulcers. 2. Mouth ulcers: can be treated by local medication, such as anti-inflammatory drugs tretinoin ointment, chlorhexidine gargle, cediriodine tablets, etc., glucocorticoid drugs dexamethasone spray, betamethasone gargle and so on. All of the above drugs should be used under the guidance of a doctor, and it is recommended to go to a regular medical institution to receive professional treatment.