Most mouth ulcers are minor and heal on their own within 10 to 14 days, but the right combination of pain relief and wound care can shorten that timeline and make the wait far more bearable. About 80% of mouth ulcers fall into the “minor” category, measuring less than 5 mm across. Larger ulcers, those over 10 mm, can take a month or longer to resolve and sometimes leave a scar. What you do in the first few days matters most.
Over-the-Counter Pain Relief
The fastest way to cut the pain is a topical numbing agent. Products containing 20% benzocaine are widely available at pharmacies and work by forming a protective film over the ulcer. To get the best result, dry the sore with a clean tissue or cotton swab before applying the gel or liquid. This helps the coating stick rather than wash away with saliva. The relief is temporary, lasting roughly 20 to 30 minutes, but reapplication throughout the day keeps the ulcer shielded while you eat and talk.
Protective barrier gels and patches serve a similar purpose. They don’t numb the area as aggressively, but they create a physical seal that prevents food, drinks, and bacteria from irritating the open sore. If benzocaine stings too much on contact, a barrier product may be a better fit.
Saltwater and Baking Soda Rinses
Rinsing with warm salt water is one of the simplest and most effective home treatments. Research from the National Dental Centre Singapore points to a roughly 7% salt concentration as effective for promoting wound healing. In practical terms, that’s about half a teaspoon of table salt dissolved in a small glass of warm water. Swish gently for 30 seconds, then spit. Doing this several times a day neutralizes the oral environment and helps the tissue recover faster.
Baking soda rinses work on a similar principle, reducing acidity in the mouth that can aggravate the ulcer. Mix half a teaspoon of baking soda in half a cup of warm water and use it the same way. Don’t rub salt directly onto the sore. That causes unnecessary pain and tissue damage without improving the outcome.
Honey as a Healing Agent
Applying honey directly to a mouth ulcer sounds like folk medicine, but clinical evidence supports it. A systematic review found that honey performed just as well as standard prescribed gels for reducing ulcer size and pain in people with common mouth ulcers. In patients with more severe oral sores caused by cancer treatment, honey actually outperformed conventional options, with significantly faster recovery times. The antibacterial and anti-inflammatory properties of honey appear to create a favorable environment for tissue repair.
To try it, dab a small amount of raw honey onto the ulcer with a clean finger or cotton swab, three times daily. It’s safe to swallow and won’t cause side effects, though it will taste sweet for a while.
When You Need Prescription Treatment
If your ulcers are large, unusually painful, or keep coming back, a prescription-strength steroid paste is the standard next step. Topical corticosteroids remain the most effective treatment backed by clinical evidence. A common option is a steroid dental paste that you press onto the sore with a cotton swab after meals and at bedtime. The paste forms a smooth, protective film. The key is pressing it gently into place rather than rubbing, which makes it crumble.
For people who get frequent outbreaks, a doctor may recommend a medicated mouth rinse containing an antimicrobial agent. These rinses reduce the severity and pain of ulcers, though they don’t prevent future episodes. In severe or resistant cases, short courses of oral steroids or other systemic medications may be necessary, but this is uncommon for typical ulcers.
Nutritional Deficiencies That Fuel Ulcers
Recurring mouth ulcers are often a signal that your body is low on certain nutrients. The three most commonly linked deficiencies are vitamin B12, folate, and iron. A randomized trial found that daily vitamin B12 supplementation significantly reduced or eliminated ulcer recurrence, and this benefit held regardless of whether participants had low B12 levels to begin with. That’s a notable finding because it suggests B12 may help even if a blood test doesn’t flag an obvious deficiency.
If you get mouth ulcers more than a few times a year, it’s worth checking your levels of these nutrients through a simple blood test. Boosting your intake of leafy greens, eggs, meat, and fortified cereals can help address mild shortfalls. For more significant deficiencies, a supplement is a straightforward fix.
Common Triggers to Avoid
Certain everyday habits make ulcers more likely. Acidic foods like citrus fruits, tomatoes, and vinegar-based dressings irritate the lining of the mouth and can trigger a new ulcer or worsen an existing one. Spicy foods do the same. During an active outbreak, sticking to bland, soft foods reduces pain and speeds healing.
Mechanical trauma is another frequent cause. Biting your cheek, aggressive brushing, or sharp edges on dental work can all break the tissue enough to start an ulcer. Using a soft-bristled toothbrush and being mindful of rough foods like chips or crusty bread helps prevent these injuries.
There has been debate about whether the foaming agent in most toothpastes, sodium lauryl sulfate (SLS), contributes to ulcers. Some studies found that people with frequent ulcers experienced fewer outbreaks after switching to SLS-free toothpaste, but a 2019 review concluded the evidence isn’t strong enough to make a definitive recommendation. Still, if you’re prone to ulcers and haven’t tried switching, it’s a low-risk experiment. SLS-free toothpastes are easy to find at most drugstores.
How to Tell if an Ulcer Needs Attention
A typical mouth ulcer is round or oval, white or yellowish in the center, and surrounded by a red border. It hurts, especially when you eat or brush near it. Minor ulcers clear up within one to two weeks without treatment. If an ulcer lasts longer than three weeks, grows larger than a centimeter, is painless, or keeps returning in clusters, those patterns warrant a closer look from a dentist or doctor. Painless ulcers that don’t heal are particularly important to have examined because they can occasionally indicate something more serious, including oral cancer.
Major aphthous ulcers, the larger variety, can persist for a month or more and sometimes scar as they heal. Herpetiform ulcers appear as clusters of tiny pinpoint sores and typically resolve within a month, though they can be intensely painful while active. Both types benefit from the treatments described above, but they’re more likely to need prescription-strength options.