Most mouth ulcers heal on their own within one to two weeks, but you can speed that process and cut the pain significantly with the right approach. The key is reducing irritation, keeping the area clean, and addressing whatever triggered the ulcer in the first place. Here’s what actually works.
Salt and Baking Soda Rinses
The simplest and cheapest option is a rinse you can make at home. Dissolve 1 teaspoon of baking soda in half a cup of warm water and swish it around your mouth for 30 seconds, then spit. A plain saltwater rinse works similarly. Both reduce the acidity inside your mouth, which is what makes the ulcer sting and slows healing. You can do this several times a day, especially after meals when food debris is most likely to irritate the sore.
Topical Numbing Gels
Over-the-counter gels and pastes containing benzocaine are the fastest way to kill the pain. Benzocaine is a local anesthetic that numbs the tissue on contact, giving you a window of relief for eating or drinking. You apply a small amount directly to the ulcer with a clean finger or cotton swab. These products also form a thin protective barrier over the sore, shielding it from food, drinks, and your teeth.
Look for oral-specific products rather than general topical anesthetics, since formulations designed for the mouth stick to wet tissue better and use safe concentrations for swallowing.
Honey as a Healing Aid
Applying honey directly to a mouth ulcer isn’t just a folk remedy. In controlled studies, ulcers treated with honey showed significantly smaller wound size and faster tissue regrowth compared to untreated wounds, with measurable differences appearing as early as day two. Honey reduces inflammation at the ulcer site while promoting the formation of new tissue.
To use it, dab a small amount of raw honey onto the ulcer with a clean cotton swab. Reapply a few times per day. It won’t numb the pain instantly the way benzocaine does, but it actively supports healing rather than just masking symptoms.
Triggers That Keep Ulcers Coming Back
If you’re dealing with recurring ulcers, something in your daily routine is likely provoking them. The most overlooked culprit is sodium lauryl sulfate (SLS), a foaming agent found in most major toothpaste brands. SLS irritates soft tissue in the mouth and is strongly associated with canker sore flare-ups. Switching to an SLS-free toothpaste is one of the single most effective changes people make for recurring ulcers. Brands like Sensodyne, Biotene, and several others sell SLS-free versions that are easy to find.
Other common triggers include citrus fruits, tomatoes, spicy foods, and anything highly acidic. Physical trauma matters too: biting the inside of your cheek, aggressive brushing, or irritation from braces or ill-fitting dental work can all start the process. Stress, poor sleep, and illness also lower your body’s defenses enough to let ulcers develop.
Nutrient Deficiencies Behind Recurring Ulcers
When ulcers keep returning despite avoiding obvious triggers, a nutritional gap may be the root cause. Several specific deficiencies are clinically linked to recurrent mouth ulcers:
- Vitamin B12: Low levels cause recurring ulcers along with fatigue and pale skin. This is especially common in vegetarians and vegans.
- Folic acid (B9): Plays a direct role in cell repair. Deficiency triggers oral inflammation, cracked lips, and ulcers.
- Iron: Low iron reduces oxygen delivery to tissues, leading to tongue soreness and slow-healing sores.
- Zinc: Supports immune function and tissue repair. Without enough zinc, ulcers heal slowly and recur more often.
- Vitamin C: Essential for collagen formation and blood vessel strength. Deficiency worsens gum bleeding and delays wound healing.
If you get mouth ulcers frequently, a blood test checking these levels can identify a correctable cause. Supplementing the specific deficiency often reduces or eliminates the problem entirely, which no amount of topical treatment can do on its own.
Minor vs. Major Ulcers
Not all mouth ulcers behave the same way. Minor ulcers, the kind most people get, are small (under 1 cm), shallow, and typically appear on the inner lips, cheeks, soft palate, or floor of the mouth. They heal within one to two weeks without scarring. You might get one at a time or several at once.
Major ulcers are larger, deeper, and significantly more painful. They penetrate further into the tissue and can leave scars when they finally heal. Major ulcers that are slow to heal, especially if accompanied by fever, joint pain, swollen lymph nodes, or eye inflammation, warrant medical evaluation. Persistent major ulcers can also be associated with HIV infection, so testing is worth considering when large ulcers don’t resolve on a normal timeline.
Chemical Cauterization for Stubborn Ulcers
For ulcers that won’t respond to home treatment, a dentist or doctor can perform chemical cauterization using a silver nitrate applicator. The procedure involves touching the tip of a thin applicator stick to the ulcer for about two minutes, which chemically seals the nerve endings and destroys the damaged tissue so fresh tissue can grow in its place. It shortens healing time noticeably.
The procedure itself is uncomfortable, so a topical anesthetic is typically applied to the area beforehand. A protective barrier of petroleum jelly is placed around the ulcer to prevent the silver nitrate from touching healthy tissue. It’s a quick in-office procedure, not a surgery, and recovery is straightforward.
How to Tell an Ulcer From Something Serious
The vast majority of mouth ulcers are harmless canker sores. But oral cancers can look similar at first glance, so it helps to know the differences. Canker sores are flat, with red, inflamed edges surrounding them. Oral cancers, by contrast, often have a small lump or bump underneath the lesion that you can feel with your tongue or finger. Cancerous lesions also lack the angry red border that’s characteristic of a canker sore.
The biggest differentiator is time. A canker sore that hasn’t healed after three weeks, or one that keeps growing rather than shrinking, needs professional evaluation. The same applies to any mouth sore that bleeds easily, feels hard or fixed in place, or comes with unexplained numbness in your lip or chin.