The effect of eating lemon for mouth ulcers is limited, because there are many causes of mouth ulcers, if it is indeed a vitamin deficiency ulcer, taking lemon should have some effect. But if it is a traumatic ulcer or an ulcer caused by endocrine factors in the human organism, in most cases, eating lemon will not have much effect. Lemon, as a frequently consumed fruit, is rich in vitamin C, and also has other vitamins and trace elements, which is certainly beneficial to the body, but its specific application to mouth ulcers, the clinical effect is not so sure. For mouth ulcers, it has the characteristics of recurrence and self-limitation, that is to say, even without special treatment, most of the mouth ulcers will heal naturally in about 1-2 weeks, but most of the healed mouth ulcers are not eradicated, and many of them will recur again after a period of time. For the treatment of mouth ulcers, you need to go to a professional medical institution for a comprehensive screening of the causes and comprehensive treatment, and simply taking lemon is not very effective in most cases.