Most mouth ulcers heal on their own within one to two weeks, but the right treatment can cut pain significantly and speed that timeline. The best approach combines pain relief, protecting the ulcer from irritation, and avoiding the foods and habits that slow healing.
Saltwater Rinses and Baking Soda
The simplest and cheapest treatment is a warm saltwater rinse. Dissolve half a teaspoon of table salt in a glass of lukewarm water, swish gently for 15 to 30 seconds, and spit. You can repeat this several times a day, especially after meals. The saline solution eases discomfort, helps draw fluid from swollen tissue, and creates a less hospitable environment for bacteria. It stings briefly on contact, but the relief afterward is noticeable.
Baking soda works similarly. Mix half a teaspoon into a glass of water and use it as a rinse. It neutralizes acids in the mouth that irritate the open sore. You can alternate between salt and baking soda rinses throughout the day.
Over-the-Counter Pain Relief
Topical numbing gels containing benzocaine are the most widely available OTC option. Benzocaine is a local anesthetic that numbs the ulcer on contact, making it easier to eat and talk. You apply a small amount directly to the dried ulcer as directed on the label. The relief is temporary, lasting roughly 15 to 30 minutes, so timing applications before meals helps the most. Don’t use benzocaine products on children under two years old, and avoid using them for longer than the label directs.
Protective pastes and barrier gels are another option. These products adhere to the surface of the ulcer and form a coating that shields exposed nerve endings from food, drinks, and the friction of your teeth and tongue. They don’t numb the area but can reduce pain by keeping irritants away from the sore. Look for bioadherent oral gels at your pharmacy.
Over-the-counter anti-inflammatory pastes containing amlexanox (5%) can also reduce both pain and healing time when applied directly to the dried ulcer two to four times daily. Availability varies by country, so check with your pharmacist.
Honey as a Topical Treatment
Applying honey directly to a mouth ulcer is one of the better-supported natural remedies. A systematic review of 13 studies found that honey reduced the severity or duration of oral ulcers in 12 of them. In studies on recurring canker sores specifically, honey performed comparably to standard pharmacy gels for both pain and ulcer size. The benefit likely comes from honey’s natural antibacterial and anti-inflammatory properties, plus its thick consistency, which physically coats the sore.
To use it, dab a small amount of raw honey onto the ulcer a few times a day. Manuka honey is often recommended, though the evidence for it specifically is mixed. One study on Manuka honey found no significant difference compared to placebo, though high dropout rates (over 50%) made those results hard to interpret. Plain raw honey is a reasonable and inexpensive option.
Foods and Irritants to Avoid
What you keep away from the ulcer matters almost as much as what you put on it. Acidic fruits like oranges, lemons, pineapples, and strawberries are common culprits that intensify pain and can slow healing. Spicy foods, hot sauce, and jalapenos have high acidity that irritates the open tissue. Coffee and alcohol are both acidic enough to aggravate an existing sore.
Hard, crunchy foods cause direct mechanical damage. Toast, potato chips, pretzels, and raw vegetables can scrape against the ulcer and reopen healing tissue. Nuts are a double problem: their sharp edges abrade the sore, and salted varieties dry out the mouth lining. Even chocolate can trigger sensitivity in some people due to a compound called theobromine.
If you get ulcers frequently, consider switching to a toothpaste that doesn’t contain sodium lauryl sulfate (SLS), the foaming agent in most commercial toothpastes. Many people find their ulcers become less frequent after making this change. SLS-free toothpastes are available at most pharmacies and health food stores.
Prescription Treatments for Severe Ulcers
When ulcers are large, extremely painful, or keep coming back, a doctor or dentist can prescribe stronger options. Topical corticosteroid pastes are the most common prescription treatment. These reduce inflammation directly at the ulcer site, and studies confirm they don’t cause the hormonal side effects associated with corticosteroids taken by mouth. You apply the paste to the dried ulcer several times a day until it heals.
Stronger corticosteroid formulations are available for stubborn cases. A prescription mouth rinse containing a corticosteroid can treat multiple ulcers at once, which is helpful if sores appear in clusters or in hard-to-reach spots. Chlorhexidine mouth rinses are another prescription option. They don’t prevent ulcers from forming, but they reduce the severity and pain of existing ones.
For severe, recurring ulcers that don’t respond to topical treatments, systemic medications exist, but they carry significant side effects and are reserved for cases where quality of life is substantially affected.
Nutritional Deficiencies and Recurring Ulcers
If you get mouth ulcers repeatedly, a nutritional deficiency could be the underlying cause. Low levels of vitamin B12, folate, and iron are all linked to recurrent ulcers. A deficiency in B12 or folate can cause a sore, red tongue alongside mouth ulcers, and you may also notice fatigue, weakness, or pale skin.
A simple blood test can identify these deficiencies. If one is found, correcting it through diet or supplements often reduces or eliminates the cycle of recurring sores. Good dietary sources of B12 include meat, fish, eggs, and dairy. Folate is abundant in leafy greens, beans, and fortified cereals. Iron comes from red meat, lentils, and spinach. If you eat a restricted diet or have absorption issues, supplementation may be necessary.
When a Mouth Ulcer Needs Medical Attention
The two-week rule is straightforward: any mouth sore that hasn’t started healing within two weeks needs professional evaluation. Most canker sores resolve well within that window. A sore that persists, grows, or keeps coming back in the same spot could signal something more serious, including oral cancer.
Specific signs that warrant a visit to your doctor or dentist include a sore with hardened or raised edges, a white or reddish patch on the inside of your mouth, unexplained loose teeth, a lump or growth in the mouth, ear pain, or difficulty swallowing. These don’t automatically mean cancer, but they require examination. Mouth ulcers that come with a high fever, severe difficulty eating or drinking, or ulcers that appear in groups of more than three or four at a time also justify a medical visit, as they may point to an underlying condition that needs its own treatment.