Most mouth sores heal on their own within 10 to 14 days, but the pain can make eating, drinking, and talking miserable in the meantime. The good news is that a combination of simple rinses, over-the-counter products, and dietary adjustments can significantly cut down on discomfort and speed up recovery.
Saltwater and Baking Soda Rinses
A homemade rinse is one of the fastest, cheapest ways to calm a mouth sore. St. Jude Children’s Research Hospital recommends this ratio: 1 teaspoon of table salt and 1 teaspoon of baking soda dissolved in 4 cups of warm water. Swish gently for about 30 seconds and spit. You can repeat this every four to six hours throughout the day.
The salt draws fluid out of swollen tissue, which reduces inflammation around the sore. Baking soda creates a slightly alkaline environment that helps neutralize acids in your mouth, acids that sting on contact with an open sore. Together, they keep the area cleaner and less painful without any chemicals.
Over-the-Counter Pain Relief
For sores that need more than a rinse, topical gels containing 20% benzocaine (sold under names like Orajel) numb the area on contact. You apply a small amount directly to the sore, and the numbing effect kicks in within a minute or two. This is especially useful right before meals so you can eat without wincing. Reapply as directed on the label, typically up to four times a day.
Protective pastes are another option. These form a thin barrier over the sore, shielding it from food, drinks, and your teeth. Some contain both a pain reliever and a coating agent. Look for products specifically labeled for canker sores or mouth sores rather than general oral care products, which may contain ingredients that irritate open tissue.
Foods That Help and Foods That Hurt
What you eat matters more than you might expect when you have a mouth sore. The U.S. Department of Veterans Affairs recommends avoiding these categories while your mouth is healing:
- Acidic foods and juices: orange, grapefruit, lemon, lime, tomato, and pineapple
- Spicy foods: anything with hot peppers, strong spices, or vinegar-based sauces
- Hard or crunchy foods: dry toast, crackers, chips, granola
- Very hot foods or drinks: let soups and beverages cool before consuming
Instead, lean toward soft, cool, or room-temperature foods. Yogurt (without crunchy mix-ins), scrambled eggs (without dry edges), mashed potatoes, smoothies, and oatmeal are all gentle on sore tissue. Cool water and milk are better beverage choices than juice or coffee.
Toothpaste and Oral Hygiene Changes
A common foaming agent in toothpaste called sodium lauryl sulfate (SLS) can aggravate mouth sores and may even trigger new ones in people who are prone to them. Switching to an SLS-free toothpaste during an outbreak, or permanently if you get frequent sores, can reduce irritation. Several major brands sell SLS-free versions, and they’re easy to find at most drugstores.
Keep brushing and flossing even when your mouth hurts. A soft-bristled toothbrush causes less friction against sore spots. Gentle, consistent oral hygiene prevents bacteria from building up around the sore and slowing the healing process.
Canker Sores vs. Cold Sores
Before you treat a mouth sore, it helps to know what you’re dealing with, because canker sores and cold sores require different approaches. According to the National Institute of Dental and Craniofacial Research, the key differences are straightforward. Canker sores appear inside the mouth, on the inner cheeks, lips, or tongue. They look like single round white or yellow spots with a red border. Cold sores (fever blisters) appear outside the mouth, typically around the border of the lips, and show up as clusters of small fluid-filled blisters.
Cold sores are caused by the herpes simplex virus and are contagious. Canker sores are not contagious and don’t have a single known cause. The rinses and topical treatments described above work for both types, but cold sores may also benefit from antiviral treatments that target the underlying virus.
Why Some People Get Sores Repeatedly
If mouth sores keep coming back, nutritional deficiencies are one of the more common and fixable causes. Research published in Canadian Family Physician links recurrent canker sores to low levels of iron, folic acid, vitamin B12, vitamin B3, and vitamin C. A simple blood test can check for these deficiencies, and correcting them through diet or supplements often reduces how frequently sores appear.
Other known triggers include stress, hormonal changes, minor mouth injuries (like biting your cheek or irritation from braces), and certain food sensitivities. Keeping a log of what you ate, your stress levels, and your sleep in the days before an outbreak can help you identify personal patterns.
Healing Timelines by Sore Type
Minor canker sores, the most common kind, typically heal within 10 to 14 days without scarring. These are small, round, and appear on soft tissue inside the mouth. Major canker sores are larger, deeper, and can take up to six weeks to heal. They sometimes leave a scar. If you’ve had a sore that has lasted longer than two weeks with no signs of improvement, that’s worth noting.
When a Mouth Sore Needs Medical Attention
Cancer Research UK guidelines recommend an urgent referral if you have a mouth ulcer that hasn’t healed after three weeks, particularly if it’s accompanied by an unexplained lump in the neck, one-sided throat pain, pain when swallowing, or red and white patches inside the mouth. A sore that keeps growing, bleeds easily, or doesn’t respond to any of the treatments above also warrants a visit. Persistent, non-healing mouth ulcers are one of the early signs doctors check when screening for oral cancer, so getting them looked at promptly is worthwhile.
Prescription Treatments
For sores that are severe, large, or keep recurring despite home care, your doctor or dentist may prescribe a steroid-based mouth rinse to reduce inflammation more aggressively than over-the-counter options can. Antimicrobial prescription rinses are sometimes used alongside other treatments to keep the area clean, though these can have side effects like temporary changes in taste and increased tooth staining.
In some cases, a corticosteroid paste applied directly to the sore can speed healing. These prescriptions are typically reserved for major canker sores or for people who get frequent outbreaks that interfere with eating and daily life. Your provider will choose a treatment based on the size, location, and frequency of your sores.