Toothpaste should not be applied to blistered lips. Most of the blisters on the lips are caused by herpes or oral diseases, and toothpaste does not have the effect of sterilization and itching, nor can it inhibit the virus, applying toothpaste has no therapeutic effect. And toothpaste contains fluoride, calcium carbonate, etc., may also cause adverse stimulation of the lip skin, resulting in allergies, redness and swelling. Blisters in the mouth should go to the stomatology department of the hospital, under the guidance of a professional doctor to apply topical application or take some oral targeted medication. 1. If it is herpes, you can use antiviral ointment under the guidance of the doctor, such as acyclovir ointment, phthalide cream, etc., and at the same time with oral antiviral drugs, such as Ciclovir, vaxilovir and so on. 2. If the blistering of the lips is caused by oral diseases, such as mouth ulcers, thrush, etc., mouth ulcers usually heal in a week or two and do not require special treatment. Thrush is caused by Candida infection, if the condition is not serious, usually do not need special treatment, just need to strengthen the oral care, pay attention to eat more fresh fruits and vegetables, drink more water, strengthen physical exercise can be. If you need treatment, you can use antifungal drugs, such as mycotoxin, fluconazole and so on. The above medications should be used under the guidance of a physician.