Most mouth ulcers heal on their own within one to two weeks, but you can speed that process and cut the pain significantly with the right combination of topical treatments, rinses, and dietary adjustments. The key is starting treatment early, ideally within hours of noticing the sore, and protecting the ulcer from further irritation while your tissue repairs itself.
Topical Treatments That Work Fastest
Over-the-counter gels, pastes, and creams applied directly to the ulcer are the most effective first step. Products containing benzocaine (sold as Anbesol, Orabase, and Zilactin-B) numb the area on contact and create a protective film over the sore. This barrier shields the raw tissue from food, drinks, and your teeth, which reduces pain and lets healing proceed without constant re-injury.
Antiseptic mouth rinses with hydrogen peroxide (like Orajel Antiseptic Mouth Sore Rinse or Peroxyl) help keep the ulcer clean and reduce the bacterial load around the wound. For ulcers that are especially large or painful, a prescription-strength steroid gel can reduce inflammation more aggressively. The critical detail with all of these: apply them as soon as you notice the ulcer forming. Waiting a few days before starting treatment means you’ve already missed the window where intervention makes the biggest difference.
Saltwater Rinses
A simple saltwater rinse is one of the most reliable home treatments. Dissolve one teaspoon of salt in eight ounces of warm water and swish gently for 30 seconds. If the rinse stings too much, cut the salt to half a teaspoon for the first day or two while the ulcer is at its most sensitive. You can rinse several times a day, especially after meals, to keep food particles from settling into the sore.
Saltwater works by drawing fluid out of swollen tissue (reducing inflammation) and creating a temporarily inhospitable environment for bacteria. It won’t numb pain the way benzocaine does, but it supports faster, cleaner healing.
Honey as a Natural Alternative
If you prefer something without active drug ingredients, honey applied directly to the ulcer three times a day has clinical support behind it. In studies comparing honey to standard medicated gels, both produced similar improvements in pain scores and ulcer size over five days. A separate trial on mouth ulcers caused by dental appliances found that honey relieved symptoms earlier than saline rinses alone. Use a small dab of raw honey, applied with a clean finger or cotton swab, and avoid eating or drinking for a few minutes afterward to let it stay in contact with the tissue.
Foods That Make Ulcers Worse
What you eat while you have an ulcer matters almost as much as what you put on it. Acidic foods and drinks lower the pH inside your mouth, which disrupts the protective layer over your tissue and directly irritates the open sore. The obvious culprits are citrus fruits, fizzy drinks, and alcohol. Less obvious triggers include strawberries and tomatoes, both of which are acidic enough to aggravate an ulcer or even help cause one in the first place.
Spicy and heavily salted foods irritate the delicate lining of your mouth and can turn a mild ulcer into something much more painful. Texture matters too. Hard, crunchy, or sharp-edged foods like crusty bread, chips, and crackers physically scrape the wound each time you chew. Stick to soft, cool, bland foods until the ulcer closes: yogurt, mashed potatoes, smoothies, scrambled eggs, and soft-cooked pasta are all safe choices.
Why Some People Get Ulcers Repeatedly
If you’re dealing with ulcers that keep coming back every few weeks or months, the problem may not be local irritation. It could be nutritional. A growing body of research links recurring mouth ulcers to deficiencies in vitamin B12, folate, and vitamin C. In one case-control study, 75% of people with recurrent ulcers had low levels of B12 and folate. Patients who received supplementation with B12, C, and folate experienced a marked reduction in how often ulcers appeared.
Each deficiency contributes differently. Low B12 causes the tissue lining your mouth to thin and become more sensitive, making it easier for ulcers to form. Folate deficiency impairs your body’s ability to repair damaged cells, so minor injuries to the lining don’t heal as quickly and are more likely to develop into full ulcers. Vitamin C deficiency slows wound healing broadly and makes your gums more fragile. If your ulcers are a recurring pattern rather than an occasional nuisance, it’s worth checking whether your diet is providing enough of these nutrients, or discussing blood work with your doctor.
Check Your Toothpaste
An ingredient called sodium lauryl sulfate (SLS), the foaming agent in most toothpastes, can increase the frequency of mouth ulcers in people with sensitive oral tissue. Research dating back to the 1990s established this link, and it holds up. SLS strips away the protective mucous layer inside your mouth, leaving the lining more vulnerable to damage. Switching to an SLS-free toothpaste is a simple, zero-cost experiment. Several brands market themselves as SLS-free specifically for people prone to ulcers. Give it four to six weeks to see if your ulcer frequency drops.
When a Mouth Ulcer Needs Medical Attention
Most mouth ulcers are small (under 5mm), painful, and gone within a week or two. But certain patterns signal something more serious. You should see a healthcare provider if an ulcer lasts longer than three weeks, if new sores appear before old ones finish healing, if you develop unusually large ulcers, or if a mouth sore is painless. A painless ulcer that won’t heal is one of the early signs of oral cancer, particularly when it appears on or under the tongue. Ulcers accompanied by fever or diarrhea also warrant a visit, as they can indicate a systemic condition rather than a simple canker sore.
Ulcers that appear on the outer surface of your lips (rather than inside your mouth) are a different category of sore entirely and may be cold sores caused by the herpes virus, which requires antiviral treatment rather than the approaches described here.