Most mouth ulcers heal on their own within 10 to 14 days, but the right combination of home care and topical treatments can cut that timeline significantly and reduce pain in the meantime. The key is starting treatment early, protecting the sore from further irritation, and giving your body the nutritional support it needs to repair tissue.
Saltwater Rinses and Hydrogen Peroxide
The simplest thing you can do right now is rinse your mouth with warm saltwater several times a day. This draws fluid out of the swollen tissue, reduces inflammation, and keeps the area clean so bacteria don’t slow down healing. Mix about half a teaspoon of salt into a cup of warm water, swish for 30 seconds, and spit.
A diluted hydrogen peroxide rinse (equal parts hydrogen peroxide and water, twice a day) works as a mild antiseptic that helps prevent secondary infection. Don’t swallow either rinse, and don’t use hydrogen peroxide more frequently than twice daily, as it can irritate healthy tissue.
Honey as a Healing Agent
Applying honey directly to a mouth ulcer is one of the more effective home remedies, and there’s real data behind it. In a controlled study comparing honey application to a standard prescription steroid paste, the honey group saw dramatically faster results. By day 5, ulcers treated with honey had shrunk from about 4.8 mm to 1.7 mm, while those treated with the steroid were still nearly 4 mm. By day 7, the honey-treated ulcers were nearly closed. Both groups fully healed by day 14, but honey got there faster.
To use this approach, dab a small amount of raw honey directly onto the ulcer a few times a day, especially after meals. It forms a protective coating, has natural antibacterial properties, and appears to promote tissue repair. It will sting briefly on contact.
Over-the-Counter Topical Treatments
Numbing gels containing benzocaine are the most widely available pharmacy option. They won’t speed healing directly, but they block pain signals for 20 to 30 minutes, which makes eating and drinking far more comfortable. Apply a small amount with clean hands directly to the ulcer. Wash your hands before and after, and avoid chewing food or gum until the numbness wears off so you don’t accidentally bite your cheek or tongue. Don’t exceed the recommended number of applications per day on the label.
Mucoadhesive gels and patches are another option. These stick to the moist surface inside your mouth and form a physical barrier over the ulcer, shielding it from food, drinks, and friction. That protection alone helps the sore heal faster because it prevents the repeated micro-damage that restarts the inflammatory cycle every time you eat.
Chlorhexidine mouthwashes, available over the counter in many countries, reduce the severity and pain of ulcers, though they don’t prevent new ones from forming. These are especially useful if you have multiple ulcers at once, since a rinse covers your entire mouth in a way a gel can’t.
Silver Nitrate Cauterization
If you need faster results and can get to a dentist or doctor, chemical cauterization with silver nitrate is worth knowing about. In a study of 65 patients, 60% of those treated with silver nitrate had fully healed ulcers by day 7, compared to 32% in the control group. The average healing time after the procedure was just 2.7 days, versus 5.5 days without it. No side effects were recorded. The procedure involves briefly touching the ulcer with a silver nitrate stick, which chemically seals the surface. It stings for a moment but provides rapid pain relief afterward.
What to Eat and Avoid
Hot, spicy, acidic, and crunchy foods are the biggest enemies of a healing ulcer. Citrus fruits, tomato-based sauces, chips, and anything with sharp edges will irritate the sore and can restart inflammation. Stick to soft, cool, or room-temperature foods while you’re healing. Yogurt, smoothies, scrambled eggs, and mashed potatoes are easy choices. Drinking plenty of water throughout the day keeps the mouth moist and supports tissue repair.
Nutritional Gaps That Slow Healing
If you get mouth ulcers repeatedly, a nutrient deficiency may be part of the problem. Studies have found a surprisingly high rate of iron and B vitamin deficiency among people with recurrent ulcers, and correcting those deficiencies reduced or eliminated recurrences in most cases.
Vitamin B12 is the best-studied. A double-blind study found that supplementing with B12 prevented recurrences even in people who weren’t deficient in it. Doses used in studies range from 3 to 1,000 mcg daily. A B-complex supplement covering B1, B2, and B6 has also been reported to help some people. A daily multivitamin containing zinc and a full B-complex is a reasonable starting point if ulcers keep coming back. For iron specifically, get your levels tested first, since excess iron supplementation carries its own risks.
Canker Sore vs. Cold Sore
Before treating any mouth sore, make sure you’re dealing with the right thing. A canker sore (aphthous ulcer) appears inside the mouth as a single round sore, usually white or yellow with a red border. It’s not contagious and its cause is unknown. A cold sore (fever blister) shows up on the outside of the mouth, around the lips, as a cluster of small fluid-filled blisters. Cold sores are caused by herpes simplex virus and require antiviral treatment, not the approaches described here.
When an Ulcer Needs Professional Attention
A mouth ulcer that hasn’t healed after three weeks needs to be evaluated by a healthcare provider. In clinical practice, any sore that persists beyond 14 days after removing obvious irritants (like a sharp tooth edge or ill-fitting denture) is flagged for closer examination. This is especially true for sores with red, textured, or color-changed tissue that doesn’t look like a typical healing ulcer. Persistent ulcers are usually nothing serious, but they occasionally signal conditions that benefit from early detection.