Most mouth ulcers heal on their own within 10 to 14 days, but you can cut that time shorter and reduce pain significantly with the right approach. The key is combining pain relief with strategies that protect the ulcer from further irritation so your body can repair the tissue faster.
Saltwater and Baking Soda Rinses
The simplest thing you can do right now is rinse with salt water. Mix 1 teaspoon of salt into 4 cups (1 quart) of water and swish gently every 4 to 6 hours. You can also add 1 teaspoon of baking soda to the same solution, which helps neutralize acid in your mouth and creates a better environment for healing. Memorial Sloan Kettering Cancer Center recommends this rinse for patients dealing with oral sores, and it works just as well for everyday mouth ulcers. The salt draws fluid out of the swollen tissue, reducing inflammation, while the baking soda shifts the pH away from the acidic conditions that slow healing.
Over-the-Counter Numbing Gels
Benzocaine gels (sold under brand names like Orajel) applied directly to the ulcer will numb the area within minutes. This doesn’t speed healing directly, but it lets you eat, drink, and talk without constant pain, which matters when you’re trying to get through your day. Apply a small amount with a clean finger or cotton swab before meals. Reapply as directed on the package, typically every few hours.
Topical antiseptic rinses containing chlorhexidine can also help by keeping the ulcer clean and preventing a secondary bacterial infection, which would slow things down.
Steroid Pastes for Faster Repair
If you want to actively speed up healing rather than just manage pain, a corticosteroid dental paste is the most effective option. These reduce the inflammatory response that keeps the ulcer raw and open. Press a small dab (about a quarter inch) onto the ulcer until a thin film forms. Don’t rub it in, or the paste will crumble. Apply it at bedtime so the steroid stays in contact with the sore overnight, and up to two or three times during the day after meals if pain is severe.
You should see meaningful improvement within a week. If the ulcer hasn’t started shrinking by then, or hasn’t resolved within two weeks, it’s worth getting a professional evaluation. Some of these pastes require a prescription, so you may need to call your dentist or doctor.
What to Eat and Avoid
What you put in your mouth during the healing window matters more than most people realize. Acidic foods and drinks lower the pH in your mouth, which disrupts the protective lining and damages proteins that help tissue repair. The obvious culprits are citrus fruits, fizzy drinks, and alcohol, but strawberries and tomatoes are common triggers that people overlook.
Spicy and salty foods irritate the delicate tissue directly. Hard, crunchy, or sharp-edged foods like crusty bread, chips, and raw vegetables can physically scrape the ulcer and reopen healing tissue. Stick to soft, cool, bland foods while the ulcer is active: yogurt, mashed potatoes, smoothies, scrambled eggs. It’s not glamorous, but avoiding re-injury is one of the fastest ways to let the ulcer close.
Low-Level Laser Therapy
If you have access to a dentist who offers low-level laser therapy, this is one of the most effective clinical options. A systematic review and meta-analysis found that laser treatment significantly reduces pain immediately and over the following one to three days, while also shortening total healing time. The procedure is quick, typically done in a single session, and painless. It’s not available everywhere and isn’t usually covered by insurance for this purpose, but if you get frequent ulcers and want the fastest possible resolution, it’s worth asking about.
Chemical Cauterization
Silver nitrate sticks offer another clinical option for rapid pain relief. A single application chemically cauterizes the nerve endings on the ulcer surface. The stick (75% silver nitrate, 25% potassium nitrate) is activated by moisture and rolled gently over the sore for up to two minutes. This is done in a clinical setting because silver nitrate burns surrounding tissue if applied carelessly, and the area around the ulcer needs to be protected with petroleum jelly first. The pain relief can be dramatic, but this is a procedure done by a professional, not something to attempt at home.
Switch to SLS-Free Toothpaste
Most commercial toothpastes contain sodium lauryl sulfate (SLS), the detergent that makes them foam. SLS irritates oral tissue and can trigger or worsen mouth ulcers. A meta-analysis of studies involving 132 patients found that switching to SLS-free toothpaste reduced the number of ulcers by about one per cycle, shortened healing duration by roughly two days, and decreased pain. The studies were small, so the evidence isn’t rock-solid, but the intervention costs nothing beyond choosing a different tube of toothpaste. Brands like Sensodyne, Biotene, and some versions of Tom’s of Maine are SLS-free. Check the ingredients list for “sodium lauryl sulfate” near the top.
This is more of a prevention strategy than an immediate fix, but if you’re someone who gets ulcers repeatedly, it’s one of the highest-impact changes you can make.
Check for Nutritional Gaps
Recurrent mouth ulcers are a recognized symptom of vitamin B12 deficiency, folate deficiency, and iron deficiency. If you’re getting ulcers frequently rather than dealing with a one-off sore, these nutritional gaps are worth investigating. A simple blood test from your doctor can identify the issue. Correcting a deficiency doesn’t heal the ulcer you have today, but it can break the cycle of getting new ones every few weeks.
When a Mouth Ulcer Isn’t Just an Ulcer
A typical mouth ulcer is painful, round or oval, and surrounded by red, inflamed tissue. It hurts most in the first few days and gradually fades. An ulcer that doesn’t heal, however, is one of the symptoms of mouth cancer. Red or white patches, a lump in your mouth or neck, pain when swallowing, changes to your speech, or unexplained bleeding or numbness are all signs that something else is going on. If your ulcer hasn’t healed after three weeks, or if it keeps coming back in the same spot, get it examined. A biopsy, where a small tissue sample is taken, is the definitive way to rule out cancer.