Most canker sores heal on their own within one to two weeks, but the right combination of home care and over-the-counter products can cut down pain and speed that timeline. These small, round ulcers with a white or yellow center and red border form inside the mouth, usually on the inner cheeks, lips, or tongue. They’re not contagious and not the same thing as cold sores, which appear outside the mouth and are caused by a virus. Canker sores have no single known cause, but several treatments can help you get through one faster.
Salt Water and Baking Soda Rinses
The simplest and cheapest first step is a homemade mouth rinse. Mix 1 teaspoon of salt and 1 teaspoon of baking soda into 1 quart (4 cups) of water. Swish gently for 30 seconds a few times a day, especially after meals. The salt draws fluid from the swollen tissue, which reduces inflammation, while baking soda neutralizes acids in the mouth that irritate the open sore. You can also use salt alone or baking soda alone at the same ratio if you prefer.
Over-the-Counter Topical Products
Numbing gels and protective pastes work best when applied as soon as you notice the sore forming. Many people feel a tingling or burning sensation before the ulcer is even visible, and that’s the ideal moment to start treatment. Products containing benzocaine (sold as Anbesol, Orabase, and Zilactin-B) temporarily numb the area so you can eat and talk more comfortably. Hydrogen peroxide rinses, like Orajel Antiseptic Mouth Sore Rinse, help keep the sore clean and reduce bacteria around the wound.
Look for adhesive pastes rather than liquid gels when possible. A paste stays on the sore longer, forming a protective barrier against food and friction from your teeth. Apply with a clean finger or cotton swab, and avoid eating or drinking for at least 15 minutes afterward so the product has time to work.
Honey as a Topical Treatment
Applying a small dab of honey directly to the sore several times a day is a surprisingly well-supported option. A systematic review of 13 studies found that honey reduced both the severity and duration of oral ulcers compared to control groups in 12 of those studies. Honey has natural anti-inflammatory and antimicrobial properties, and it forms a soothing coating over the wound. Plain, unprocessed honey works fine. Just apply it with a clean finger and try not to lick it off immediately.
Foods to Avoid While You’re Healing
What you eat matters almost as much as what you put on the sore. Acidic foods like citrus fruits, tomatoes, and vinegar-based dressings directly irritate the exposed tissue. Spicy foods, salty chips, and rough-textured items like crusty bread or tortilla chips can reopen the wound or make inflammation worse. Coffee and other caffeinated drinks are also common triggers.
Stick to soft, bland, cool foods while the sore is active. Yogurt, smoothies, mashed potatoes, scrambled eggs, and oatmeal are all easy on the mouth. Drinking through a straw can help keep liquids away from the sore if it’s on your inner cheek or lip.
Switch to an SLS-Free Toothpaste
If you get canker sores repeatedly, your toothpaste may be part of the problem. Sodium lauryl sulfate (SLS) is a foaming agent found in most conventional toothpastes, and it’s linked to more frequent and more painful outbreaks. A systematic review found that people who switched to SLS-free toothpaste had significantly fewer ulcers, shorter healing times (about 2 fewer days per sore), and less pain compared to when they used regular toothpaste. Brands like Sensodyne, Biotene, and certain versions of Tom’s of Maine are SLS-free. Check the ingredient list on the back of the tube.
When a Sore Won’t Go Away
For stubborn or especially large canker sores, a dentist or doctor can apply a chemical cauterizing agent directly to the sore. One product called Debacterol works by chemically sealing the ulcer surface, which can reduce healing time to about a week even for more serious sores. Silver nitrate is another option that may not speed healing but typically provides noticeable pain relief. These are quick in-office procedures, not surgeries.
For severe or recurring outbreaks, a prescription steroid mouth rinse containing dexamethasone can reduce inflammation across multiple sores at once. A prescription-strength topical like fluocinonide gel is another step up from over-the-counter options.
Nutritional Deficiencies That Cause Recurring Sores
People who get canker sores frequently, especially without an obvious trigger like biting their cheek, often have an underlying nutritional gap. Vitamin B12 deficiency is one of the most commonly identified causes of recurrent canker sores. Low levels of iron, folate (vitamin B9), and zinc are also linked to repeated outbreaks. All four nutrients play roles in immune function, cell repair, or wound healing.
If you’re getting canker sores every month or two, it’s worth asking your doctor to check these levels with a simple blood test. Correcting a deficiency through diet or supplements often reduces how often sores appear. Good dietary sources include leafy greens and legumes for folate, red meat and shellfish for iron and B12, and nuts and seeds for zinc.
Canker Sores vs. Cold Sores
These two get confused constantly, but they’re completely different conditions. Canker sores only appear inside the mouth, are not caused by a virus, and are not contagious. Cold sores (fever blisters) appear on or around the lips, are caused by the herpes simplex virus, and spread through direct contact. If your sore is on the outside of your lip or in a cluster of small blisters, that’s a cold sore and requires antiviral treatment instead.
Sores That Need Professional Attention
A canker sore that hasn’t healed within two weeks is no longer behaving like a typical canker sore. Persistent mouth sores that bleed easily and don’t resolve in that timeframe are a recognized early sign of oral cancer, according to the Cleveland Clinic. This doesn’t mean every slow-healing sore is cancer, but it does mean you should have it evaluated. The same applies to sores that are unusually large, spreading, accompanied by fever, or making it genuinely difficult to eat or drink.