Most mouth ulcers cause intense stinging that peaks in the first three to four days, then gradually fades as the sore heals over 10 to 14 days. You can cut that pain significantly with a combination of topical numbing agents, protective barriers, and simple dietary adjustments. Here’s what works, starting with the fastest options.
Quick Relief With Numbing Gels
Over-the-counter benzocaine gels are the most accessible way to dull ulcer pain fast. These come in 10% (regular strength) and 20% (maximum strength) formulations and work by temporarily blocking the nerve signals at the ulcer’s surface. Apply a small amount directly to the sore with a clean finger or cotton swab. Pain relief typically lasts around two hours per application, giving you a window to eat or drink more comfortably.
If benzocaine isn’t available, look for gels containing lidocaine or choline salicylate, which work similarly. Apply these before meals for the most practical benefit, since eating is usually when ulcer pain is worst.
Salt Water Rinses
A salt water rinse is the simplest home remedy and one recommended by the NHS. Dissolve half a teaspoon of salt in a glass of warm water (warm helps the salt dissolve fully), swish it around your mouth for 15 to 30 seconds, then spit it out. You can repeat this as often as you like throughout the day. Salt water won’t numb the pain the way benzocaine does, but it reduces bacteria around the ulcer, helps keep the area clean, and can ease inflammation over time. The first few seconds will sting, then the soreness typically settles.
Protective Patches and Barrier Films
One reason mouth ulcers hurt so much is that the raw tissue is constantly exposed to saliva, food, and the movement of your tongue and cheeks. Mucoadhesive patches, sold in most pharmacies, stick directly over the ulcer and create a physical seal. Research on these patches found something striking: even patches without any active medication reduced pain nearly as well as medicated versions, simply because the mechanical barrier alone shields the exposed nerve endings from irritation.
These patches typically stay in place for several hours, protecting the ulcer from contact with food, drinks, and oral bacteria. They’re especially useful if your ulcer is in a spot that rubs against your teeth or gets irritated while you talk.
Honey as a Natural Alternative
If you prefer something from the kitchen, honey has genuine clinical support. A randomized controlled trial comparing honey to a topical corticosteroid found that honey significantly reduced ulcer pain, size, and redness. Dab a small amount of raw honey directly onto the ulcer a few times a day. It forms a soothing coating and has natural antibacterial properties that may help prevent secondary infection. The downside is that it washes away quickly, so you’ll need to reapply often.
Foods That Make It Worse
What you eat matters as much as what you apply. The biggest culprits for aggravating mouth ulcers are acidic foods and drinks: citrus fruits, tomatoes, strawberries, fizzy drinks, and alcohol. People often don’t think of tomatoes and strawberries as acidic, but both can trigger significant stinging on an open sore. Spicy and salty foods irritate the delicate lining of the mouth in the same way.
Texture matters too. Hard, crunchy, or sharp foods like crusty bread, chips, and crackers can physically scrape against the ulcer. Stick to soft, cool, bland foods while the sore is healing. Yogurt, scrambled eggs, mashed potatoes, and smoothies are all easy options. Drinking through a straw can help liquids bypass the ulcer entirely.
When Pain Persists: Prescription Options
If over-the-counter options aren’t enough, a doctor or dentist can prescribe a corticosteroid rinse. These work by reducing the inflammation that drives ulcer pain. The typical approach is a medicated mouthwash that you swish around and spit out twice a day. Clinical trials show these rinses decrease pain noticeably. One thing to be aware of: prolonged use of a steroid rinse can sometimes lead to a secondary fungal infection in the mouth, so these are meant for short-term use during flare-ups rather than ongoing prevention.
Switch Your Toothpaste
This is one of the most underrated changes you can make if you get mouth ulcers repeatedly. Many common toothpastes contain sodium lauryl sulfate (SLS), a foaming agent that can irritate the oral lining. A systematic review of clinical trials found that switching to an SLS-free toothpaste consistently reduced the number of ulcers, the duration of each episode, and pain levels. If you’re someone who gets ulcers every few weeks, checking your toothpaste ingredient list is a low-effort change worth trying. SLS-free options are widely available from most major brands.
Nutritional Deficiencies and Recurring Ulcers
Occasional mouth ulcers are normal. But if you’re getting them frequently, a nutritional deficiency could be the underlying driver. Vitamin B12 deficiency is one of the most common culprits, and it can cause recurrent ulcers along with a burning sensation in the mouth and changes in taste. Iron and folate deficiencies are also linked to repeated outbreaks. A simple blood test from your doctor can check for these. Correcting a B12 deficiency, whether through supplements or dietary changes, often reduces or eliminates recurring ulcers entirely.
How Long Healing Takes
Setting realistic expectations helps you know whether your ulcer is healing normally or needs attention. There are three types, and they heal on very different timelines:
- Minor ulcers make up about 80% of cases. They’re under 10 mm across and heal within 10 to 14 days without scarring.
- Major ulcers are larger than 1 cm, account for 10 to 15% of cases, and can take up to six weeks to heal. These often leave a scar.
- Herpetiform ulcers appear as clusters of many tiny sores (2 to 3 mm each) that can merge into larger irregular patches. They typically resolve in 10 to 14 days.
Any ulcer that hasn’t improved after two weeks, keeps growing, or interferes with your ability to eat and drink warrants a professional evaluation. A biopsy is generally recommended for oral lesions that persist beyond that two-week mark, particularly to rule out other conditions.