Most canker sores heal on their own within one to two weeks, but the right combination of pain relief, protective barriers, and trigger avoidance can cut that timeline shorter and make the wait far more bearable. There’s no instant cure, but several approaches genuinely speed healing rather than just masking symptoms.
Why Some Treatments Work and Others Don’t
The biggest challenge with treating a canker sore is keeping anything on it long enough to help. Your mouth is a wet, moving environment. Rinses provide quick pain relief through their moisturizing effect, but they wash away in seconds and don’t meaningfully aid healing. Gels last longer but still get wiped off by your tongue, cheeks, and saliva. This is why treatments that physically stick to the sore or reduce inflammation at the source tend to work best.
Saltwater and Baking Soda Rinses
A simple rinse won’t heal a canker sore on its own, but it keeps the area clean and reduces bacteria that can slow recovery. Memorial Sloan Kettering recommends mixing 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. It will sting briefly, but the discomfort fades quickly.
OTC Numbing Gels and Protective Pastes
Benzocaine gels (sold as Orajel and similar brands) are local anesthetics that numb the sore on contact. They’re useful before meals or when pain spikes, but they wear off quickly and need reapplication. For longer-lasting coverage, look for oral adhesive pastes that physically coat the ulcer and shield it from friction and food. These stick better than standard gels and give the tissue underneath more uninterrupted time to repair.
Mucoadhesive patches and films represent the next step up. These are thin, dissolvable patches you press directly onto the sore. They stay in place far longer than gels because they’re designed to resist saliva and tongue movement. Some contain hyaluronic acid, a compound that actively promotes tissue healing by stimulating cell growth and reducing inflammation. A 0.2% concentration of hyaluronic acid has been shown to reduce ulcer duration and slightly lower recurrence rates.
Honey as a Treatment
Honey is one of the more surprising options with real evidence behind it. Clinical trials have found that applying honey to minor canker sores reduces pain, shrinkage, and redness at rates comparable to prescription steroid creams. Honey acts as a natural anti-inflammatory and also forms a protective coating over the sore. Patients in studies reported better compliance with honey than with steroid treatments, likely because it tastes better and feels less medicinal. Dab a small amount of raw honey directly onto the sore a few times daily, letting it sit as long as possible before eating or drinking.
Chemical Cauterization for Fast Pain Relief
If you need faster results, chemical cauterization is an option. Debacterol is a topical solution that chemically burns the surface of the sore, which sounds aggressive but can reduce healing time to about a week. Silver nitrate, another cauterizing agent, hasn’t been shown to speed healing but does provide significant pain relief. Both are typically applied by a dentist or doctor in a single visit. The application stings intensely for a few seconds, then the pain from the sore drops dramatically.
Prescription Options for Severe Sores
When canker sores are large, numerous, or keep coming back, prescription steroid rinses can tamp down the inflammatory response driving the ulcers. These are swished around the mouth and spit out rather than swallowed. One risk to be aware of: steroid rinses can create conditions for fungal infections in the mouth, so they’re reserved for cases where over-the-counter options aren’t enough.
Switch Your Toothpaste
This is one of the most overlooked and easiest changes you can make. Most commercial toothpastes contain sodium lauryl sulfate (SLS), a foaming agent at concentrations between 1% and 3%. SLS strips away the protective mucus layer lining your mouth, thins the tissue, and at concentrations above 0.5% actively causes cell death in the upper layers of your oral lining. That damage makes the tissue far more vulnerable to ulcers forming in the first place.
In a double-blind crossover study, people who brushed with SLS-containing toothpaste developed significantly more canker sores than those using SLS-free alternatives. Switching to an SLS-free toothpaste has been shown to reduce the number of ulcers, how long they last, and how much they hurt. Brands like Sensodyne, Biotene, and several others make SLS-free versions that are easy to find at any pharmacy. If you get canker sores more than a few times a year, this single switch is worth trying before anything else.
Nutritional Deficiencies That Fuel Recurrence
Deficiencies in iron, folate, and B vitamins (particularly B12) show up in 18% to 28% of people with recurrent canker sores, compared to about 8% of the general population. That’s a meaningful gap, though it’s worth noting that the majority of canker sore sufferers have perfectly normal levels of these nutrients. If your sores keep returning and you can’t identify an obvious trigger like toothpaste or food irritation, a blood test checking these levels is a reasonable next step. Correcting a deficiency, if one exists, can reduce how often sores appear.
What to Avoid While Healing
Acidic foods like tomatoes, citrus, and vinegar-based dressings directly irritate open sores and can extend healing time. Spicy foods, rough-textured chips and crackers, and very hot beverages all do the same. Stick to softer, cooler, blander foods until the sore closes. If a sharp tooth edge or dental appliance seems to be triggering sores in the same spot, a dentist can smooth or adjust it.
When a Canker Sore Needs Attention
Most canker sores are harmless, but certain patterns warrant a closer look. The Mayo Clinic flags these specific situations: sores that last longer than two weeks, unusually large sores, new sores developing before old ones finish healing, sores that extend onto the outer lip border, pain that doesn’t respond to any self-care, difficulty eating or drinking, or high fever accompanying the sores. A sore that won’t heal after two weeks in particular needs professional evaluation to rule out other conditions.