Most mouth ulcers heal on their own within two to three weeks, but you don’t have to wait that out in pain. A combination of simple home care, over-the-counter products, and smart prevention habits can cut healing time, reduce discomfort, and keep ulcers from coming back.
Saltwater Rinses: The Simplest Starting Point
A warm saltwater rinse is one of the fastest things you can do when an ulcer first appears. Mix one teaspoon of salt into eight ounces of warm water and swish gently for 30 seconds before spitting it out. If that stings too much, drop to half a teaspoon for the first day or two. You can repeat this several times a day, especially after meals.
Saltwater works on multiple levels. It shifts the pH inside your mouth toward alkaline, creating an environment where bacteria struggle to survive. It also kills bacteria directly through osmosis, pulling water out of bacterial cells. Beyond germ control, salt water promotes the migration of fibroblasts, the cells responsible for wound repair, and supports the production of the structural material your tissue needs to close the wound.
Over-the-Counter Products That Help
If a saltwater rinse isn’t enough, topical products applied directly to the ulcer can numb pain and protect the sore from further irritation. The most widely available option is benzocaine gel (sold as Anbesol, Orabase, or Zilactin-B), which temporarily numbs the area so you can eat and drink more comfortably. Apply it as soon as you notice a new ulcer forming for the best results.
Hydrogen peroxide rinses designed for mouth sores (like Orajel Antiseptic Mouth Sore Rinse) help keep the ulcer clean and reduce bacterial buildup around the wound. You can also dab a small amount of milk of magnesia directly onto the ulcer a few times a day. The antacid coats the sore’s surface, creating a temporary barrier that reduces contact with food, saliva, and acids.
Protective pastes that form a film over the ulcer are another useful category. These stick to the moist tissue inside your mouth and shield the sore for several hours, which is especially helpful before meals.
When Ulcers Need Prescription Treatment
Ulcers that are large, unusually painful, or keep recurring may need something stronger. A prescription steroid gel containing fluocinonide can reduce the inflammation driving the pain and swelling. For widespread or severe outbreaks, your doctor or dentist may prescribe a steroid mouthwash. One common version involves dissolving a steroid tablet in a few teaspoons of water and swishing once daily, ideally after eating or brushing. You avoid eating or drinking for at least 30 minutes afterward so the medication stays in contact with the tissue.
For ulcers that resist other treatments, chemical cauterization with silver nitrate is an option. A clinician applies the chemical directly to the sore, which destroys the damaged nerve endings and surface tissue. In one study comparing silver nitrate to a placebo, patients treated with silver nitrate reported an average healing time of just 2.7 days after the procedure, with a range of two to four days. The application itself can sting briefly, but pain relief often follows quickly.
Minor vs. Major Ulcers: What to Expect
Not all mouth ulcers follow the same timeline. Minor ulcers, the kind most people get, are small, round, and shallow. They typically heal within 10 to 14 days without scarring. Major ulcers are larger (over one centimeter across), deeper, and significantly more painful. These can take up to six weeks to fully heal and may leave a scar. If you’re dealing with a major ulcer, prescription treatment is worth pursuing early rather than waiting it out.
Nutritional Gaps That Fuel Ulcers
Recurrent mouth ulcers are sometimes a signal that your body is low on specific nutrients. Vitamin B12, iron, and folate deficiencies have all been linked to repeated outbreaks. If you’re getting ulcers frequently, especially clusters of them, it’s worth checking whether a nutritional gap is involved. This is particularly relevant if you follow a restricted diet, have heavy menstrual periods (which can deplete iron), or have digestive conditions that affect nutrient absorption. Correcting a deficiency can sometimes reduce or eliminate recurrent ulcers entirely.
Preventing the Next Outbreak
Some ulcers are triggered by physical irritation: biting the inside of your cheek, sharp edges on braces or dental work, or aggressive brushing with a hard-bristled toothbrush. Switching to a soft-bristled brush and getting sharp dental edges smoothed can make a real difference.
There’s been debate about whether sodium lauryl sulfate (SLS), the foaming agent in most toothpaste, contributes to ulcers. SLS can irritate the delicate lining of the mouth, and some people with recurrent ulcers report improvement after switching to an SLS-free toothpaste. However, the clinical evidence is mixed. A 2019 review found there wasn’t enough data to confirm that SLS-free toothpaste reduced ulcer frequency, duration, or pain. Still, if you’re getting frequent ulcers and haven’t tried removing SLS, it’s a low-risk experiment.
Certain foods are common triggers for people prone to ulcers. Acidic fruits like oranges and tomatoes, spicy foods, and rough-textured snacks like chips or crusty bread can either initiate an ulcer or aggravate one that’s forming. Paying attention to which foods precede your outbreaks helps you identify your personal triggers. Stress is another well-recognized factor, though harder to control.
How to Tell if It’s Something More Serious
A standard mouth ulcer is flat, often has inflamed red edges, and hurts, especially in the first few days. It then gradually becomes less painful as it heals. Oral cancers behave differently. Early oral cancers are often painless, and you may feel a small lump or bump beneath the surface of the lesion. Canker sores tend to stay flat.
Pay attention to any sore that doesn’t heal within three weeks, a small spot that grows larger, a white patch that turns red, or a lesion that starts bleeding when it previously didn’t. These changes warrant a professional evaluation. The two-to-three-week healing window is the key benchmark: a normal ulcer should be visibly improving well within that timeframe.