Canker sores are often treated with aspirin as a home remedy, according to It is generally agreed that the use of aspirin on canker sores is safe.


Canker sores are oral ulcers that appear on the inside of the mouth or gums. They last from a few days to a couple of weeks.

Aspirin History

Aspirin has been used for centuries to reduce fever and relieve pain. Aspirin is also an anti-inflammatory and blood thinner. One negative side effect is stomach distress.

Canker Sore Treatment

According to Prevention, to treat canker sores with aspirin, you grind up a small portion of a non-coated aspirin pill and add a few drops of water to make a paste, then apply it to the sore. Aspirin relieves the pain and stops the festering sore.

Length of Treatment

Aspirin in paste form should be left on the sore no more than five to 10 minutes. It should then be rinsed off. Treatment may be repeated later if pain reoccurs, and the sore is not healed. Generally, canker sores treated with aspirin heal within a day or two.


Aspirin left on a canker sore more than five to 10 minutes may cause “aspirin burn,” according to There are no other known safety factors, except for potential allergy to aspirin. Children under the age of 12 should not use this treatment.