Most mouth ulcers heal on their own within 10 to 14 days, but the right combination of rinses, topical treatments, and habit changes can cut down pain significantly and speed the process along. What you do in the first day or two matters most, since that’s when inflammation peaks and the ulcer is most sensitive to irritation.
What Type of Ulcer You’re Dealing With
Not all mouth ulcers behave the same way, and knowing what you have helps set realistic expectations for healing. The most common type, minor aphthous ulcers, are less than 1 cm across and clear up in 7 to 14 days without scarring. These are the round, shallow sores most people picture when they think of a mouth ulcer.
Major aphthous ulcers are larger than 1 cm and can persist for up to six weeks. They often leave scarring on the tissue inside your mouth. Herpetiform ulcers are a third, less common variety that appear as clusters of tiny sores (0.1 to 0.3 cm each) that can merge into larger, irregular patches. These make eating and speaking especially painful, and they can last anywhere from 10 days to over three months. If your ulcers are unusually large, appear in clusters, or keep coming back, the approach you take will differ from treating an occasional minor sore.
Salt Water and Baking Soda Rinses
A simple rinse is the cheapest and most immediately available treatment. Memorial Sloan Kettering Cancer Center recommends mixing 1 teaspoon of salt and 1 teaspoon of baking soda into 1 quart (4 cups) of water. You can also use either ingredient on its own at the same ratio: 1 teaspoon per quart. Swish gently for 30 seconds and spit. Repeat several times a day, especially after meals, to keep food particles out of the ulcer and reduce the bacterial load around the wound.
The rinse will sting briefly on contact, but it creates a cleaner environment for healing. Baking soda also neutralizes acids in your mouth that can further irritate open tissue. This won’t dramatically shorten healing time, but it reduces the chance of a secondary infection and keeps pain more manageable between meals.
Over-the-Counter Pain Relief
Topical numbing gels and liquids are the fastest way to get temporary relief. Products containing benzocaine (common brand: Orajel) or lidocaine work by blocking pain signals at the surface of the ulcer. Lidocaine oral solutions are typically formulated at 2%, and the numbing effect lasts long enough to eat a meal comfortably. Don’t reapply more frequently than every three hours, and cap usage at eight applications in a 24-hour period.
Protective pastes and patches that form a barrier over the ulcer are another option. These stick to the moist tissue inside your mouth and shield the sore from contact with food, teeth, and your tongue. Look for products labeled as oral wound care or canker sore patches at most pharmacies. They won’t numb the area, but the physical barrier can make a bigger difference than painkillers for ulcers in high-friction spots like the inside of the cheek or along the gum line.
Prescription Treatments for Stubborn Ulcers
If over-the-counter options aren’t enough, a doctor or dentist can prescribe a corticosteroid paste. These reduce inflammation directly at the ulcer site, which shortens healing time and brings down pain more effectively than numbing agents alone. The paste is applied by pressing a small amount (about a quarter inch) onto the sore until a thin film forms. You don’t rub it in. It will feel gritty at first but smooths out into a slippery protective layer.
Apply the paste at bedtime so the medication stays in contact with the ulcer overnight. For more severe sores, your provider may recommend applying it two or three times daily, ideally after meals when the area is relatively clean. These pastes are most effective when started early, so if you have a history of major or recurring ulcers, it’s worth having a prescription on hand before the next one appears.
How Mouth Ulcers Heal
Understanding the healing timeline helps you gauge whether things are progressing normally. In the first few days, your immune system floods the area with white blood cells to clear debris and fight bacteria. This is the inflammatory stage, and it’s when the ulcer hurts the most. Redness and swelling are signs of this process working, not signs that something is wrong.
After the initial inflammation subsides, new tissue begins forming to fill the wound. Blood vessels grow into the area to deliver oxygen and nutrients, and you may notice a white, pink, or slightly bumpy surface developing over the ulcer. This granulation tissue is a healthy sign. In the final stage, collagen fibers strengthen and reorganize, and the tissue gradually returns to normal. For minor ulcers, this entire process wraps up within two weeks. Major ulcers can take six weeks, and the tissue may never fully return to its original texture.
What Causes Recurring Ulcers
If you’re getting mouth ulcers regularly, treatment alone won’t solve the cycle. Several nutritional deficiencies are closely linked to recurrent ulcers, particularly low levels of vitamin B12, folate, and iron. These deficiencies can cause a sore, reddened tongue along with frequent ulcers. A simple blood test can identify whether any of these are low, and supplementation often reduces how often ulcers return.
Stress is another well-established trigger. Many people notice ulcers appearing during high-pressure periods at work or after poor sleep. Hormonal fluctuations, particularly around menstruation, also increase susceptibility. Minor injuries from biting your cheek, aggressive tooth brushing, or rough-edged dental work can trigger individual sores in people who are already prone to them.
Preventing the Next One
One of the simplest changes you can make is switching to a toothpaste that doesn’t contain sodium lauryl sulfate (SLS), the foaming agent in most standard toothpastes. In a study published in Acta Odontologica Scandinavica, participants who switched from SLS-containing toothpaste to an SLS-free version saw their ulcer count drop from an average of 14.3 to 5.1 over the study period. That’s roughly a 64% reduction. SLS-free toothpastes are widely available and cost about the same as regular options. Check the ingredients list on the back of the tube.
Beyond toothpaste, pay attention to your personal triggers. Keep a simple log of what you ate, how stressed you were, and whether you had any mouth injuries in the days before an ulcer appeared. Patterns tend to emerge quickly. Common food triggers include citrus fruits, tomatoes, chocolate, coffee, and spicy foods. You don’t necessarily need to eliminate these permanently, but reducing them during high-stress periods or when you feel the early tingle of a developing ulcer can help.
Using a soft-bristled toothbrush and brushing gently, especially along the gums and inner cheeks, reduces the small tissue injuries that can trigger ulcers. If a rough tooth edge or dental appliance keeps causing sores in the same spot, getting it smoothed or adjusted by a dentist removes the problem at its source.
Signs an Ulcer Needs Medical Attention
A single ulcer that hasn’t healed after three weeks deserves a professional evaluation, even if it’s not particularly painful. Ulcers larger than 1 cm, sores that keep returning in the same spot, or ulcers accompanied by fever, difficulty swallowing, or unexplained weight loss all warrant a closer look. In some cases, a persistent ulcer may need a biopsy to rule out other conditions, including oral cancer. This is especially true for ulcers that appear on the side or underside of the tongue, the floor of the mouth, or the soft palate, since these are higher-risk locations.