Most canker sores heal on their own within one to two weeks, but you can speed up the process and cut the pain significantly with the right combination of home care, over-the-counter products, and trigger avoidance. The key is acting early: treatments work best when applied as soon as you feel that telltale tingling or spot forming inside your mouth.
Home Rinses That Reduce Pain and Healing Time
A simple saltwater rinse is the most accessible first step. Dissolve half a teaspoon of salt in a cup of warm water and swish for 30 seconds, several times a day. This draws fluid out of the sore, which temporarily reduces swelling and pain. A baking soda rinse works similarly: one teaspoon dissolved in half a cup of warm water helps neutralize acids in the mouth that irritate the open tissue.
Both rinses also keep the area cleaner, which matters because bacteria in the mouth can slow healing. Neither will make a canker sore vanish overnight, but consistent use throughout the day shortens the overall timeline and makes eating less miserable in the meantime.
Over-the-Counter Gels and Patches
Topical products containing benzocaine, a local anesthetic, numb the sore on contact and provide temporary pain relief that lasts long enough to get through a meal. These come as gels, pastes, and liquids that you dab directly onto the ulcer. They work best when you dry the area with a tissue first so the product sticks to the sore rather than washing away with saliva.
Protective pastes and patches create a physical barrier over the ulcer, shielding it from food, drinks, and your teeth. This reduces re-irritation, which is one of the main reasons canker sores linger. For best results, apply any topical product as soon as the sore appears. Waiting until it’s fully developed means you’ve already lost several days of potential benefit.
Prescription Options for Severe Sores
When a canker sore is unusually large, lasts longer than two weeks, or keeps coming back, prescription treatments offer a bigger step up. A steroid-containing mouth rinse reduces both pain and inflammation, and a prescription numbing rinse can make eating and drinking manageable again. Prescription-strength topical pastes are also available and tend to work faster than OTC versions.
Chemical cautery is another option your dentist or doctor can perform in the office. A topical solution is applied directly to the sore to destroy the damaged tissue, which can reduce healing time to about a week. Silver nitrate, a different cautery agent, helps with pain but hasn’t been shown to speed healing itself.
For people with frequent, severe outbreaks that don’t respond to anything else, oral steroid medications are sometimes used as a last resort. Oral medications originally designed for other conditions, like certain gut-coating drugs, are occasionally repurposed as well.
Laser Treatment for Immediate Relief
Some dental offices now offer low-level laser treatment for canker sores. The procedure takes just a few minutes, kills bacteria at the sore site, and provides near-immediate pain relief. Proponents report that a single session can allow the sore to heal within about two days, a significant improvement over the usual one-to-two-week timeline. It’s not widely available everywhere, but it’s worth asking your dentist about if you deal with frequent or particularly painful sores.
How Long Canker Sores Take To Heal
Minor canker sores, the most common type, heal within a few weeks without scarring. Pain typically improves within a few days even without treatment. Major canker sores, which are deeper and larger, can take months to heal and sometimes leave scars. A third type, called herpetiform canker sores (clusters of tiny ulcers), generally heals within about two weeks.
If you’re using home remedies and OTC products consistently, you can expect to shave several days off these timelines. The biggest payoff comes from starting treatment early and avoiding re-irritation from food and drink.
Foods and Drinks That Make Things Worse
Acidic foods are the biggest culprits. Citrus fruits, tomatoes, strawberries, fizzy drinks, and alcohol all irritate the exposed tissue and can trigger new sores in people who are prone to them. Spicy and heavily salted foods also inflame the delicate lining of the mouth enough to set off an ulcer or worsen an existing one.
Texture matters too. Hard, crunchy, or sharp-edged foods like crusty bread, chips, and raw vegetables can physically scrape the sore and delay healing. While you have an active canker sore, softer foods at moderate temperatures will cause the least discomfort.
Switch to SLS-Free Toothpaste
Sodium lauryl sulfate (SLS) is a foaming agent found in most mainstream toothpastes, and it’s a well-documented trigger for canker sores. A meta-analysis found that people who switched to SLS-free toothpaste had roughly one fewer ulcer per outbreak, nearly two fewer days of ulcer duration, and significantly less pain compared to those using regular toothpaste. The number of episodes also dropped.
If you get canker sores more than a couple of times a year, switching toothpaste is one of the simplest, cheapest changes you can make. Several major brands sell SLS-free versions, and they clean your teeth just as effectively.
Vitamin Deficiencies That Fuel Recurrence
Recurring canker sores are linked to deficiencies in vitamin B12 and folate. Both nutrients are essential for DNA repair and the constant cell turnover that keeps the lining of your mouth intact. When levels drop too low, the tissue becomes fragile and more prone to breaking down into ulcers.
B12 deficiency can also cause a sore, inflamed tongue and increased sensitivity throughout the mouth. Folate deficiency leads to similar problems: pale, fragile tissue and a burning sensation that predisposes you to ulcers. If you’re getting canker sores frequently and can’t identify an obvious trigger like acidic food or SLS toothpaste, it’s worth having your B12 and folate levels checked with a simple blood test. Correcting a deficiency through supplementation or dietary changes can dramatically reduce how often sores appear.
Signs a Canker Sore Needs Professional Attention
Most canker sores are harmless, but certain patterns warrant a closer look. A sore that lasts more than two weeks, bleeds and won’t heal, or is accompanied by swelling in your neck should be evaluated by a doctor or dentist. The same goes if you’re getting more, larger, or more severe sores than usual, or if over-the-counter treatments aren’t helping with the pain at all.
Pay attention to other symptoms happening alongside the sore. Fever, swollen lymph nodes, persistent fatigue, or digestive problems alongside mouth ulcers can point to an underlying condition that’s driving the outbreaks. A change in your voice, like hoarseness lasting more than two weeks, is another signal to get checked.