Most canker sores on the tongue heal on their own within 10 to 14 days, but the right treatment can cut pain and shrink the sore significantly faster. Because the tongue moves constantly and touches everything you eat and drink, canker sores there tend to hurt more than ones on the gums or inner cheeks. The good news: several inexpensive options work well, and you can start most of them right now with things already in your kitchen.
Make Sure It’s Actually a Canker Sore
Canker sores and cold sores are often confused, but they’re completely different. Canker sores appear inside the mouth, including on the tongue, and look like a single round white or yellow sore with a red border. Cold sores appear outside the mouth, usually around the lips, and show up as clusters of small fluid-filled blisters caused by the herpes simplex virus. Canker sores are not contagious, and their exact cause is unknown, though the immune system plays a central role. In people prone to canker sores, certain immune cells attack the mouth’s surface tissue, and that destruction is fueled by ongoing inflammation at the site.
You’ll often feel a burning or tingling sensation on the tongue anywhere from 2 to 48 hours before the sore actually appears. That prodromal window is a good time to start treatment, since acting early can reduce the severity.
Salt Water and Baking Soda Rinses
A simple rinse is the fastest thing you can do. Mix 2 cups of warm water with half a teaspoon of baking soda and a quarter teaspoon of salt, swish it around your mouth for 30 seconds or so, then follow up with a rinse of plain water. Repeat this several times a day, especially after meals. The baking soda neutralizes acids in the mouth that irritate the sore, while the salt draws fluid from the inflamed tissue to reduce swelling. It won’t taste great, but it reliably takes the edge off.
Over-the-Counter Pain Relief
For direct pain relief on the tongue, look for a topical gel or ointment containing 20% benzocaine. Products like Orajel and Red Cross Canker Sore medication use this concentration. Apply a small amount directly to the sore up to four times a day. Benzocaine numbs the area within a minute or two, making it much easier to eat and talk. The effect is temporary, lasting roughly 30 to 60 minutes, but it’s useful for getting through meals.
Adhesive canker sore patches are another option worth considering. These small discs, about the size of a child’s fingernail, stick over the sore and create a physical barrier against food, teeth, and saliva. In a clinical trial of 46 people with new canker sores, about four-fifths of those who used patches reported no pain after three days, compared to only two-fifths of people who went untreated. After seven days, sores in the patch group had shrunk by 90 percent, while untreated sores had actually grown slightly. Patches can be tricky to keep in place on the tongue since it moves so much, but if you can get one to stick, the protection is substantial.
Honey as a Topical Treatment
Plain honey applied directly to the sore is surprisingly effective. In a controlled study, patients who dabbed honey on their canker sores four times a day for five days saw significantly better results than untreated groups in three measures: ulcer size, days of pain, and redness. Use a clean finger or cotton swab to apply a small amount, and try not to eat or drink for a few minutes afterward to let it sit. Raw, unprocessed honey is ideal. It’s a low-risk option that works especially well combined with rinses.
Prescription Options for Severe Sores
If your canker sore is large, extremely painful, or keeps coming back, a doctor or dentist can prescribe a steroid dental paste. This is applied as a thin film directly over the sore, ideally at bedtime so the medication stays in contact with the tissue overnight. For more severe cases, it can be applied two or three times a day after meals. The paste reduces the immune-driven inflammation that sustains the sore.
Possible side effects include localized burning, irritation, or dryness at the application site. In rare cases with prolonged use, the oral tissue can thin out or develop a secondary infection. These pastes are meant for short-term use on specific sores, not as an ongoing treatment.
Major canker sores, the less common and more aggressive type, can take up to a month to heal and sometimes leave scars. These larger sores are the ones most likely to need prescription treatment.
Avoiding Triggers That Cause Recurrence
If you get canker sores repeatedly, your toothpaste may be part of the problem. Sodium lauryl sulfate (SLS), the foaming agent in most toothpastes, has been identified by dental researchers as a significant contributor to canker sore formation. Switching to an SLS-free toothpaste is one of the simplest changes you can make, and for some people it dramatically reduces how often sores appear. Brands like Sensodyne (some formulas), Verve, and Biotene offer SLS-free options.
Other common triggers include acidic foods like citrus and tomatoes, spicy dishes, and mechanical irritation from biting your tongue or rough dental work. Stress is another well-documented trigger. About one-third of people with recurrent canker sores have a family history of them, pointing to a genetic component in how the immune system responds to these triggers.
Vitamin B12 and Nutritional Deficiencies
Low levels of vitamin B12, folate, and iron are all associated with recurrent canker sores. A randomized, double-blind trial published in the Journal of the American Board of Family Medicine tested a daily sublingual dose of 1,000 micrograms of B12 taken at bedtime for six months. The results showed a significant reduction in canker sore recurrence over the treatment period, regardless of whether patients had low B12 levels at the start. If you get canker sores frequently, it’s worth having your B12 and iron levels checked, and a daily B12 supplement is a low-cost, low-risk intervention to try.
Signs a Canker Sore Needs Medical Attention
Any oral ulcer that lasts longer than two weeks without healing should be evaluated by a dentist or doctor. This is the standard referral threshold used in clinical practice, because ulcers that persist beyond that window can occasionally indicate something other than a simple canker sore. You should also seek evaluation if the sore is unusually large, if you develop a fever alongside the ulcer, if sores appear in clusters of many at once, or if they recur so frequently that one hasn’t finished healing before the next appears.