The 14 Best Canker Sore Treatments, According to Professionals

Milk of Magnesia Paste

Another effective treatment for canker sores is to apply milk of magnesia paste to the sore. Milk of magnesia is a common over-the-counter medication mainly used to relieve constipation. The active ingredient in milk of magnesia is magnesium hydroxide, which works by drawing water into the intestine, thereby softening the stool and making it easier to pass. 

However, magnesium hydroxide can also be used for other purposes. For example, it can be applied topically to help heal canker sores or other mouth ulcers. This over-the-counter medication works by neutralizing acid and coating the ulcer, which protects it from bacteria and promotes healing. Milk of magnesia is inexpensive and easy to find, so it’s worth keeping on hand in case you get a pesky canker sore.

To use this remedy, wet a cotton ball with milk of magnesia and apply it to the sore. Leave it in place for 5 to 10 minutes, and then rinse your mouth with warm water. Repeat this process 3 to 4 times a day until the sore has healed. As with any medication, it is crucial to follow the directions on the label and speak with a healthcare professional if you have any questions.