Most canker sores heal on their own within one to two weeks, but you can cut that timeline shorter and reduce pain significantly with the right approach. The key is starting treatment early, keeping the sore protected, and avoiding anything that irritates it further.
What Actually Speeds Up Healing
No single remedy makes a canker sore vanish overnight, but several treatments can shave days off the process and make those days far more tolerable. The most effective options work by either reducing inflammation, protecting the raw tissue from further irritation, or both.
Over-the-counter products containing benzocaine numb the sore on contact, which helps with eating and talking. Brands like Orajel and Zilactin-B coat the lesion and form a protective film over it. This barrier shields the sore from food, drinks, and your teeth, giving the tissue underneath a better chance to heal without repeated damage. Apply these after meals and before bed for the best results.
If OTC products aren’t cutting it, a prescription steroid paste (triamcinolone) is the next step up. You press a small amount onto the sore with a cotton swab to form a smooth film. Don’t rub it in, as the paste becomes crumbly and loses its protective quality. It reduces inflammation directly at the site, which both eases pain and helps tissue repair faster. Your dentist or doctor can prescribe it quickly, often over the phone if you’re a known patient with recurring sores.
Home Remedies Worth Trying
A salt water rinse is the simplest thing you can do right now. Dissolve about half a teaspoon of salt in a cup of warm water, swish it around the sore for 30 seconds, and spit. This draws fluid out of the swollen tissue, temporarily shrinks the sore, and creates a less hospitable environment for bacteria. It stings initially but often feels better afterward. Repeat three or four times a day.
Baking soda rinses work similarly. Mix one teaspoon into half a cup of warm water and swish. The mild alkaline solution helps neutralize acids in your mouth that can aggravate the sore.
Honey applied directly to the sore is another option with some clinical backing. In one small trial, participants who applied honey three times daily for five days reported improvements in pain and ulcer size comparable to those using a standard prescription gel. Honey won’t dramatically outperform conventional treatments, but it’s safe, readily available, and its thick consistency naturally coats the sore.
In-Office Treatments for Stubborn Sores
If you have a canker sore that’s unusually painful or large (bigger than a pea), a dentist can offer faster relief. Chemical cauterization with a product called Debacterol destroys the damaged nerve endings on the surface of the sore. The result is a noticeable drop in pain, often within minutes. Silver nitrate is another cautery option that helps with pain, though it hasn’t been shown to speed actual healing.
These in-office treatments are most useful for major canker sores, the kind that exceed one centimeter in diameter and can take months to heal on their own, sometimes leaving scars. For those, professional intervention is worth pursuing early rather than waiting it out.
What to Avoid While It Heals
Half of getting rid of a canker sore quickly is not making it worse. Acidic foods like tomatoes, citrus fruits, and vinegar-based dressings directly irritate the exposed tissue. Spicy foods do the same. Crunchy foods like chips and crackers can physically scrape the sore and restart the damage cycle. Stick to soft, bland foods until the sore closes up.
Sodium lauryl sulfate, a foaming agent in many toothpastes, is a known irritant for canker sores. Switching to an SLS-free toothpaste during an outbreak (and potentially long-term if you get sores frequently) can reduce irritation and may help prevent future ones. Sensodyne and several “natural” brands skip this ingredient.
Preventing the Next One
If you get canker sores repeatedly, a vitamin B12 deficiency may be part of the picture. A randomized, double-blind trial published in the Journal of the American Board of Family Medicine found that taking 1,000 micrograms of sublingual B12 daily for six months significantly reduced the frequency of recurrent canker sores, regardless of whether participants were initially deficient in B12. The tablets dissolve under the tongue before bed, and they’re widely available without a prescription.
Other nutritional gaps linked to frequent canker sores include iron, zinc, and folate. If you’re getting sores more than a few times a year, it’s worth asking your doctor to check these levels with a simple blood test. Stress is another well-documented trigger. You can’t always eliminate it, but recognizing the pattern helps you start treatment at the first tingle rather than waiting until the sore is fully formed.
Minor mouth injuries from braces, dental work, or accidentally biting your cheek are common triggers too. Orthodontic wax over sharp brackets and being careful with hard toothbrush bristles can reduce the mechanical damage that kicks off a sore.
Is It Actually a Canker Sore?
Canker sores appear inside the mouth as single, round, white or yellow sores with a red border. Cold sores (fever blisters) look different: they’re clusters of small fluid-filled blisters that form outside the mouth, typically around the lip border. The distinction matters because cold sores are caused by the herpes simplex virus and require antiviral treatment, while canker sores are not contagious and respond to the anti-inflammatory approaches described above.
A sore that hasn’t healed after two weeks, keeps coming back in the same spot, or is unusually large warrants a visit to your dentist or doctor. Persistent sores that don’t follow the normal healing pattern occasionally need a biopsy to rule out other conditions.