Most mouth sores heal on their own within one to two weeks, but the right care can cut pain significantly and speed up recovery. The key is identifying what type of sore you have, protecting it from further irritation, and giving your body the nutritional building blocks it needs to repair the tissue.
First, Identify Your Type of Mouth Sore
The two most common mouth sores are canker sores and cold sores, and they require different approaches. The simplest way to tell them apart is location. Cold sores appear on the outside of your mouth, typically around the border of your lips. They look like clusters of small, fluid-filled blisters and are caused by the herpes simplex virus (usually type 1). They’re contagious.
Canker sores show up inside your mouth, on the inner cheeks, lips, or tongue. They’re usually a single round sore, white or yellow in the center with a red border. They’re not caused by a virus, they’re not contagious, and their exact cause isn’t fully understood. Triggers include mouth injuries (like biting your cheek or brushing too hard), stress, smoking, and deficiencies in iron, folic acid, or vitamin B12. Both types often announce themselves with a burning or tingling sensation before the sore fully forms.
Salt Water Rinse: The Simplest First Step
A warm salt water rinse is one of the most effective and accessible things you can do. Mix 1 teaspoon of salt into 8 ounces of warm water, swish it gently around the affected area for 30 to 60 seconds, then spit it out. If that concentration stings too much, drop to half a teaspoon. Do this several times a day, especially after meals. Salt water draws fluid out of inflamed tissue, which reduces swelling and creates a less hospitable environment for bacteria. It won’t make a sore disappear overnight, but it meaningfully reduces discomfort and supports cleaner healing.
Over-the-Counter Pain Relief
For canker sores that make eating or talking painful, a topical numbing gel containing benzocaine can provide temporary relief when applied directly to the sore. These are available at most pharmacies without a prescription.
Hydrogen peroxide rinses (1.4% concentration, which is what most mouth sore rinse products contain) also help by cleaning the area and reducing bacteria. The standard approach is to swish about 10 milliliters around the sore for at least one minute, then spit it out. You can do this up to four times daily, ideally after meals and at bedtime. Don’t swallow the rinse.
Protective pastes that form a barrier over the sore can also help. These stick to the wet tissue inside your mouth and shield the ulcer from food, drink, and friction while it heals. Look for oral adhesive pastes specifically designed for mouth sores.
Honey as a Healing Agent
Medical-grade honey, particularly manuka honey, has shown real promise for mouth sores. In clinical settings, children with chemotherapy-related mouth sores who used honey paste experienced healing within three days and reported significantly less pain than those who received standard care alone. The antibacterial and anti-inflammatory properties of honey appear to create favorable conditions for tissue repair. If you want to try this at home, dab a small amount of manuka honey directly onto the sore a few times a day. Regular grocery store honey is less studied for this purpose.
Foods That Slow Healing
What you eat while a sore is active matters more than most people realize. Acidic foods like oranges, grapefruits, tomatoes, and anything containing vinegar (pickles, many salad dressings) cause a burning sensation on contact with open sores and can delay tissue repair. Spicy foods irritate the entire mouth area. Salty foods like chips and salted nuts create a similar burning effect. Even stretching your mouth wide to eat something like a large sandwich or pizza slice can reopen a healing sore, especially in the later stages when a scab is forming.
Stick to soft, bland, room-temperature foods while your sore heals. Think yogurt, oatmeal, scrambled eggs, bananas, and well-cooked pasta. Cold foods like smoothies or ice pops can also feel soothing.
When Sores Keep Coming Back
Recurring canker sores often point to an underlying nutritional deficiency. Low levels of vitamin B12, iron, or folate are well-established triggers. Vitamin B12 or folate deficiency can cause a persistently sore or red tongue along with recurring mouth ulcers. A simple blood test can identify these deficiencies, and correcting them through diet or supplements often reduces how frequently sores appear.
Your toothpaste could also be a factor. Sodium lauryl sulfate (SLS) is the ingredient that makes toothpaste foam. It’s a surfactant that breaks down oils effectively, but it can also irritate sensitive oral tissue, cause dryness, and trigger canker sores in some people. Switching to an SLS-free toothpaste is a low-effort change that has helped many people with chronic canker sores reduce their frequency.
Prescription Options for Severe Sores
If your sores are large, unusually painful, or last longer than two weeks, a doctor or dentist can prescribe stronger treatments. Prescription-strength corticosteroid pastes reduce the number of days you’re dealing with an active ulcer and lower pain levels, though they don’t prevent future outbreaks. Another prescription paste, designed specifically for canker sores, was shown in a large study to achieve complete healing in 21 percent of patients within just three days, compared to 8 percent of untreated patients. These are applied directly to the dried sore several times a day.
For cold sores specifically, antiviral medications work best when started at the first sign of tingling, before blisters fully form. They shorten the outbreak and reduce severity.
How Long Healing Takes
Minor canker sores, the kind most people get, typically heal within 7 to 14 days without leaving a scar. Major canker sores, which are larger and deeper, can take several weeks and sometimes leave scarring. Cold sores generally follow a 7 to 10 day cycle from tingling to complete healing, though antiviral treatment can shorten this.
If a mouth sore hasn’t improved after two weeks, keeps growing, or is accompanied by a high fever, difficulty swallowing, or sores appearing in other parts of your body, those are signs that something beyond a routine canker sore or cold sore is going on and warrants professional evaluation.