Most canker sores heal on their own within two weeks, but the right combination of treatments can cut that time shorter and reduce pain significantly along the way. The key is managing irritation, using proven topical treatments, and avoiding the foods and products that slow the process down.
What Actually Speeds Up Healing
A 2025 umbrella review of 41 studies found that topical corticosteroids and low-level laser therapy consistently shortened healing time and reduced pain better than other options. Hyaluronic acid gels also showed favorable short-term results with minimal side effects. These are the treatments with the strongest clinical backing, and most are available over the counter or through a quick dental visit.
Over-the-counter corticosteroid pastes designed for oral use create a protective barrier over the sore while reducing inflammation at the tissue level. You apply them directly to the ulcer, typically after meals and before bed, so the medication stays in contact with the sore as long as possible. Numbing gels containing benzocaine won’t speed healing directly, but they reduce pain enough that you can eat and drink normally, which matters because staying nourished supports your body’s repair process.
For sores that are particularly painful or slow to respond, a dentist can use laser therapy or chemical cauterization to eliminate bacteria in the area and accelerate tissue repair. This is a quick in-office procedure, not a major intervention.
Rinses That Help
A baking soda rinse is one of the simplest and most widely recommended options: dissolve 1 teaspoon of baking soda in half a cup of warm water and swish gently. This neutralizes acids in your mouth and creates a less hostile environment for healing tissue. A basic salt water rinse works similarly by drawing fluid out of the swollen tissue and keeping the area clean. You can alternate between the two several times a day, especially after eating.
Avoid mouthwashes that contain alcohol. They’ll sting on contact and can dry out the tissue around the ulcer, which slows down the repair process rather than helping it.
Switch to SLS-Free Toothpaste
Sodium lauryl sulfate (SLS) is the foaming agent in most toothpastes, and it has a measurable effect on canker sores. A systematic review of crossover trials found that people who switched to SLS-free toothpaste had fewer ulcers, shorter ulcer duration, fewer episodes overall, and less pain. All four measures improved consistently.
If you get canker sores regularly, switching toothpaste is one of the easiest long-term changes you can make. Several major brands sell SLS-free versions, and they’re widely available at pharmacies. Even if you only have a single sore right now, removing this irritant from your daily routine gives the tissue a better chance to heal without being re-aggravated twice a day.
Foods That Slow Healing
What you eat during the healing window matters more than most people realize. Three categories of food actively irritate the ulcer bed and can delay recovery:
- Acidic foods and drinks: citrus fruits, tomatoes, berries, pineapple, vinegar, coffee, alcohol, and fruit juice. The acid causes a burning sensation on contact and can damage the fragile new tissue forming over the sore.
- Spicy foods: hot peppers, hot sauce, salsa, curry, and anything with cayenne or chili powder. Capsaicin directly irritates exposed tissue.
- Hard or crunchy foods: chips, pretzels, crusty bread, popcorn, granola, and crackers. These can physically scrape the sore and reopen the wound.
Temperature matters too. Very hot food and drinks increase pain and can irritate the healing surface. Stick to lukewarm or cool options. Soft, bland foods like yogurt, scrambled eggs, mashed potatoes, oatmeal, and smoothies are the easiest to tolerate while a sore is active.
Vitamin B12 for Pain Relief
A randomized, double-blind trial tested topical vitamin B12 on canker sores and found a significant pain reduction after just two days of treatment. The group using B12 ointment reported pain scores roughly five times lower than the placebo group. While B12 is better studied as a pain management tool than a healing accelerator, less pain means less stress on the tissue and fewer disruptions to eating and sleeping, both of which support faster recovery.
What Counts as a Concerning Sore
Most canker sores are minor and resolve without complications. But certain patterns signal something beyond a typical ulcer: sores lasting longer than two weeks, unusually large sores, new sores developing before old ones have healed, sores extending onto the outer lip border, pain that doesn’t respond to any home treatment, difficulty eating or drinking, or a high fever alongside the sores. Any of these warrant a visit to your doctor or dentist.
If a sharp tooth edge or dental appliance seems to be triggering repeated sores in the same spot, a dentist can smooth or adjust the surface. Removing the mechanical irritant often stops the cycle entirely.