Most canker sores heal on their own in 4 to 14 days, but several treatments can cut that timeline significantly. The right approach depends on how severe your sore is and what you have available, but even simple home remedies can make a real difference in both pain and healing speed.
What a Normal Timeline Looks Like
Minor canker sores, the kind most people get, are typically 2 to 5 millimeters across and resolve without treatment in one to two weeks. They go through a predictable progression: a tingling or burning sensation for a day or two, then a shallow white or yellowish ulcer surrounded by redness, followed by gradual shrinking and re-covering of the tissue. Everything below is aimed at compressing that timeline or reducing pain while it runs its course.
Salt Water Rinses
A warm salt water rinse is the simplest thing you can do right now. Mix about one teaspoon of table salt into a cup (250 ml) of warm water and swish gently for 30 seconds, then spit. Lab research shows that saline at this concentration stimulates the migration of gum tissue cells and boosts production of the structural proteins needed to rebuild tissue. The chloride in salt is the active driver of that cell movement. Rinse two to three times a day, especially after meals.
Honey as a Topical Treatment
Applying a small dab of honey directly to the sore is one of the most effective home options available. In a clinical trial comparing honey to a prescription steroid paste (triamcinolone), the honey group healed in an average of 2.7 days compared to 5.9 days for the steroid group and 7.1 days for the untreated control group. That’s a striking result for something in your pantry. Use raw, unprocessed honey if possible. Apply it directly to the ulcer a few times a day, ideally after rinsing your mouth. It reduces both ulcer size and pain.
Over-the-Counter Patches and Gels
Mucoadhesive patches, sold under various brand names at pharmacies, stick directly over the sore and create a physical barrier that shields it from food, drinks, and your tongue. This alone speeds things up considerably. In one study, untreated canker sores took about 10 days to heal, while sores covered with a plain (unmedicated) patch healed in roughly 6 days. Medicated versions containing pain relievers or anti-inflammatory agents did even better, resolving sores in about 1.5 days on average. Pain relief was equally dramatic: untreated patients reported pain lasting 134 hours, while those using medicated patches reported pain disappearing in about 5 hours.
OTC gels and pastes containing benzocaine or other numbing agents won’t speed healing as dramatically, but they coat the sore and reduce pain so you can eat and talk more comfortably. Look for products specifically labeled for oral ulcers.
Switch to SLS-Free Toothpaste
Sodium lauryl sulfate (SLS) is a foaming agent in most toothpastes, and it irritates the lining of your mouth. A systematic review of clinical trials found that switching to an SLS-free toothpaste consistently reduced the number of canker sores, how long each sore lasted, how many episodes occurred, and how much pain people experienced. This won’t heal the sore you have right now overnight, but it can shorten it and prevent the next one. Several major brands sell SLS-free options, usually marketed for sensitive mouths.
Vitamin B12 for Recurring Sores
If you get canker sores repeatedly, a vitamin B12 supplement may help break the cycle. A review of clinical studies found that 1,000 micrograms of B12 taken daily under the tongue for six months significantly reduced outbreaks, the number of ulcers per episode, and how long each ulcer lasted. A B12 ointment applied directly to the sore also reduced pain levels within two days. This is especially worth trying if your diet is low in B12 (common with vegetarian or vegan diets, or in older adults with absorption issues).
Laser Treatment at a Dentist’s Office
If you have a particularly painful or stubborn sore, some dentists offer low-level laser therapy. A controlled study found that canker sores treated with a diode laser healed in about 3 days compared to nearly 9 days for untreated sores. The treatment is quick, usually painless, and provides near-immediate pain relief. It’s not necessary for a typical sore, but it’s worth knowing about if you deal with frequent or severe outbreaks.
What Doesn’t Help Much
Silver nitrate cauterization, sometimes suggested as a way to “burn away” a canker sore, provides pain relief but doesn’t actually speed healing. A randomized controlled trial found that by day seven, healing rates were nearly identical between the silver nitrate group (83% healed) and the placebo group (89% healed). The difference was not statistically significant. So while cauterization may reduce pain in the short term, it won’t get you to the finish line any faster.
Avoiding Common Irritants While Healing
No treatment works well if you keep aggravating the sore. Acidic foods like citrus, tomatoes, and vinegar-based dressings directly irritate the exposed tissue and can extend healing time. Spicy foods, crunchy chips, and hard bread edges cause repeated mechanical trauma. Alcohol-based mouthwashes sting and can inflame the area further. Stick to bland, soft foods and gentle rinses until the sore closes.
If you notice your sores tend to appear after biting your cheek, after dental work, or in spots where a bracket or denture rubs, addressing the source of trauma is just as important as treating the ulcer itself. Orthodontic wax over sharp hardware can prevent sores from forming in the first place.
When a Canker Sore Needs Attention
A sore that persists for more than two weeks after you’ve removed any obvious irritants warrants a professional evaluation. The same applies to sores that are unusually large (bigger than a centimeter across), sores that keep coming back in clusters, or any mouth ulcer accompanied by fever or difficulty swallowing. Most canker sores are harmless, but a non-healing oral ulcer can occasionally signal something else that needs to be ruled out.