Does putting salt on a canker sore help?

We all dread canker sores when they show up. They are very painful and can impact various facets of day-to-day living. Maybe you have heard that putting salt on the ulcer will help it heal faster. So you want to give it a try, even though you know that the pain will be excruciating. So the question is: Does putting salt on a canker sore help?

The answer is not so simple. Sodium chloride, also known as salt, is an astringent. It works by extracting water from the canker sore, which helps the ulcer contract. This may help it heal faster. Salt also extracts water from the bacteria living on the ulcer to prevent them from replicating, thus helping to speed the healing process.

However, along with removing water to shrink and kill the bacteria, salt will also extract water from your repair cells and kill them. The ulcer bed is filled with inflammatory cells, granulation tissues, engorged capillaries, and repair cells called fibroblasts. You don't want to kill off the fibroblasts. This may actually slow down healing. 

Putting salt on a canker sore to speed healing is mainly anecdotal and there is no scientific data to suggest it works. Despite this, some people are willing to bear the pain and put salt on an ulcer. However, putting salt on an ulcer may irritate it even further, causing it to be more inflamed and interfere with healing. Some people even faint when putting salt on their canker sore due to the intense pain! 

Try using a salt mouth rinse for your canker sore.

Instead of using pure salt, you may want to try using a salt mouthwash, which is more tolerable and less irritating. In addition, there is scientific data to demonstrate the efficacy of a salt rinse on canker sores. This study confirms the benefits of a sodium chloride (salt) rinse for oral ulcers.

The salt solution may be all that is needed to kill the bacteria living on the surface of the ulcer bed. Remember, if you use pure salt on the canker sore, it may penetrate deeper and kill off your repair cells too. To make a salt water gargle for your canker sore, follow the recipe below:

• 1/2 cup warm water
• 1 teaspoon salt
• Add a few drops of your favorite essential oil
• You may experience a stinging sensation during the swishing process
• You can swish or gargle 3-4 times a day

Sandie Tran, Pharm.D.