Most mouth sores heal on their own within one to two weeks, but you can speed that process and cut the pain significantly with the right approach. The key is identifying what type of sore you’re dealing with, then matching it with the appropriate treatment.
Canker Sores vs. Cold Sores
The two most common mouth sores look and behave differently, and treating them requires different strategies. Canker sores (aphthous ulcers) appear inside the mouth, usually on the inner cheeks, lips, or tongue. They’re round, white or yellow with a red border, and they’re not contagious. Their exact cause is unknown, but they can be triggered by stress, mouth injuries (like biting your cheek), smoking, or nutritional deficiencies in iron, folate, or vitamin B12.
Cold sores show up on the outside of the mouth, around the lips. They appear as clusters of small, fluid-filled blisters and are caused by herpes simplex virus type 1 (HSV-1). Unlike canker sores, cold sores are contagious. The virus stays in your nerve cells permanently and can reactivate periodically, so cold sores tend to come back in the same area.
Home Remedies That Actually Help
A saltwater rinse is one of the simplest and most effective things you can do. Mix about one teaspoon of salt into a cup of water (roughly 250 mL) and swish for 30 seconds, then spit. Research shows that a saline solution at this concentration stimulates the cells responsible for wound repair, boosting production of collagen and other proteins your tissue needs to close up. It also helps keep the area clean. You can repeat this several times a day.
Baking soda rinses work similarly. Dissolve a teaspoon in a cup of water and swish. This neutralizes acids in your mouth that can irritate the sore. You can also make a paste with a small amount of water and apply it directly to the ulcer.
Applying ice or holding a cold drink against the sore temporarily numbs pain. Honey, dabbed directly onto a canker sore, has mild antibacterial and anti-inflammatory properties that some people find helpful.
Over-the-Counter Treatments
Topical products containing benzocaine (sold as Anbesol, Orabase, and similar brands) numb the sore on contact and can make eating and drinking far more comfortable. These come as gels, pastes, and creams. For best results, apply them as soon as you notice a sore forming.
Antiseptic mouth rinses containing hydrogen peroxide (like Orajel Antiseptic Mouth Sore Rinse) help keep the area disinfected and may speed healing. Look for products specifically labeled for mouth sores rather than using straight hydrogen peroxide from the bottle, which can be too concentrated and irritate surrounding tissue.
For cold sores specifically, antiviral creams containing docosanol are available without a prescription. These work best when applied at the first tingle, before the blister fully forms.
What to Avoid While You’re Healing
Spicy foods aren’t just painful on an open sore. They’re actively making things worse. Capsaicin, the compound that gives chili peppers their heat, activates pain receptors in your mouth’s tissue. When those receptors sit in damaged, inflamed tissue, they fire more intensely. Alcohol has a similar effect: it lowers the temperature threshold at which pain receptors activate, meaning even the normal warmth of your mouth is enough to trigger a burning sensation on the sore.
Acidic foods like citrus fruits, tomatoes, and vinegar-based dressings also irritate open sores. Stick to softer, blander foods until the sore closes. Yogurt, oatmeal, mashed potatoes, and smoothies are easier to tolerate. Avoid crunchy foods like chips and crackers that can physically scrape the ulcer.
Switch Your Toothpaste
If you get canker sores repeatedly, check your toothpaste for sodium lauryl sulfate (SLS), the foaming agent in most toothpaste brands. A systematic review of clinical trials found that switching to SLS-free toothpaste significantly reduced the number of ulcers, the duration of each ulcer, the number of episodes, and pain levels across all four measures. SLS-free options are widely available at most drugstores. This single change can make a meaningful difference if you’re someone who gets canker sores more than a few times a year.
Nutritional Deficiencies and Recurring Sores
People who get canker sores frequently often have lower-than-normal intake of specific nutrients. Research comparing people with recurrent canker sores to the general population found that affected individuals consumed significantly less vitamin B12 (about 7% below the recommended daily intake) and folate (about 20% below). Iron deficiency has also been linked to recurrent outbreaks. Roughly 14 to 18 percent of people with recurring canker sores have a detectable nutritional deficiency.
The encouraging part: correcting these deficiencies through diet or supplements leads to measurable improvement in symptoms. Foods rich in B12 include meat, fish, eggs, and dairy. Folate is abundant in leafy greens, legumes, and fortified grains. If your sores keep coming back despite good oral hygiene and avoiding triggers, a simple blood test can check whether a deficiency is contributing.
When Sores Need Professional Treatment
Dentists and doctors generally follow a “two-week rule.” If a mouth sore hasn’t healed within two weeks, it needs to be examined. This is true even if the sore isn’t particularly painful, because persistent sores can occasionally indicate something more serious.
You should also seek care sooner if you have a sore larger than a centimeter across, a high fever accompanying the sore (common with a first-time herpes infection), sores that keep coming back in rapid succession, or pain so severe you can’t eat or drink. Major canker sores, the larger and deeper variety, can take months to heal and sometimes scar. For these, a dentist or doctor may prescribe a steroid paste or rinse to reduce inflammation and accelerate healing. Laser therapy is another option for severe or stubborn sores. In one clinical study, ulcers treated with a single laser session healed in about 3 days on average, compared to nearly 9 days without treatment, and 28 out of 30 patients experienced complete pain relief immediately after the procedure.
Typical Healing Timelines
Minor canker sores, the most common type, heal within one to two weeks without scarring. You’ll typically feel the worst pain in the first three to four days, with gradual improvement after that. Major canker sores (deeper, larger ulcers) can persist for weeks to months. Herpetiform canker sores, which appear as clusters of tiny ulcers, usually resolve within about two weeks and don’t scar.
Cold sores follow a predictable cycle of tingling, blistering, weeping, crusting, and healing that takes roughly 7 to 10 days. Antiviral treatment started during the tingling phase can shorten this by a day or two. Over-the-counter pain relief and keeping the area clean are the main strategies for managing the process comfortably.