Most mouth sores heal on their own within one to two weeks, but you can speed things up and reduce pain with a few simple strategies. The key is protecting the sore from further irritation, keeping your mouth clean, and avoiding the foods and products that slow recovery.
Figure Out What Kind of Sore You Have
The two most common types of mouth sores are canker sores and cold sores, and they require different approaches. Canker sores (aphthous ulcers) appear inside the mouth, usually on the inner cheeks, lips, or tongue. They look like single round white or yellow sores with a red border. They’re not contagious and don’t have a single known cause.
Cold sores (fever blisters) show up outside the mouth, typically around the border of the lips. They appear as clusters of small fluid-filled blisters and are caused by the herpes simplex virus. Cold sores are very contagious and often need antiviral treatment rather than the home care described below. The rest of this article focuses primarily on canker sores and other interior mouth sores, since those are what most people are dealing with when they search for relief.
Rinse With Salt Water
A warm saltwater rinse is the simplest and most effective home treatment. It draws fluid from the swollen tissue, helps keep the area clean, and creates an environment that supports healing. St. Jude Children’s Research Hospital recommends this formula: mix 1 teaspoon of table salt and 1 teaspoon of baking soda into 4 cups of warm water. Swish gently for 30 seconds and spit. You can repeat this several times a day, especially after meals.
The baking soda helps neutralize acids in your mouth that can irritate the sore. If you don’t have baking soda, plain salt water still works. Just avoid swishing too aggressively, which can aggravate the tissue.
Protect the Sore From Irritation
One reason mouth sores hurt so much is that every bite of food and every brush of your tongue reopens the wound. Over-the-counter oral gels and pastes create a thin protective film over the sore, shielding it from contact with food, teeth, and saliva. Look for products labeled as oral wound care or canker sore patches at your pharmacy. These adhesive patches stick directly to the sore and can hold medication against it for hours, which both reduces pain and delivers treatment right where it’s needed.
If you don’t have access to patches or gels, dabbing a small amount of milk of magnesia directly on the sore a few times a day can coat and soothe it.
Avoid Foods That Slow Healing
Spicy, acidic, and crunchy foods are the biggest offenders. The UK’s National Health Service specifically advises people with mouth ulcers to avoid spicy foods because they irritate the open tissue. Citrus fruits, tomatoes, vinegar-based dressings, and salty snacks like chips can all sting on contact and delay healing.
Stick with soft, bland foods while your sore heals. Yogurt, oatmeal, scrambled eggs, bananas, and cool soups are easy on the mouth. Drinking through a straw can help liquids bypass the sore, especially if it’s on your inner lip or cheek.
Switch to SLS-Free Toothpaste
Sodium lauryl sulfate (SLS) is a foaming agent in most toothpastes, and it can trigger or worsen mouth sores. SLS disrupts the protective barrier of the tissue lining your mouth, making it easier for irritants to penetrate. In a study of patients with recurrent oral ulcers, about 54% experienced fewer outbreaks after switching to SLS-free toothpaste for three months, and pain scores dropped significantly by six months.
SLS-free toothpastes are widely available. Check the ingredients list for “sodium lauryl sulfate” and choose a brand without it. This is especially worth trying if you get canker sores repeatedly. While it may not eliminate them entirely, since mouth sores have multiple contributing factors, reducing this one irritant can make a noticeable difference in how often sores appear and how much they hurt.
Check for Nutritional Gaps
Recurring mouth sores can signal that your body is low on certain nutrients. Vitamin B12 deficiency is one of the most well-documented nutritional links, and it can cause recurrent ulcers, tongue inflammation, and burning sensations in the mouth. Deficiencies in iron, zinc, folic acid, and other B vitamins (B1, B2, and B6) have also been connected to chronic oral sores.
If you get mouth sores frequently, especially more than a few times a year, it’s worth having your levels checked through a blood test. Iron deficiency in particular can show up as pale tissue inside the mouth along with recurring sores. Correcting these deficiencies through diet or supplements often reduces how often sores come back. Good dietary sources of B12 include meat, fish, eggs, and fortified cereals. Iron-rich foods include red meat, spinach, and lentils. Zinc is found in shellfish, seeds, and nuts.
What a Normal Healing Timeline Looks Like
Minor canker sores, the kind most people get, typically heal within 7 to 14 days without scarring. The first two to three days tend to be the most painful, and the sore gradually shrinks from there. With proper care, some people see significant improvement within just a few days. One study found that 21% of patients using a topical treatment achieved complete healing within three days, compared to 8% of untreated patients, which gives a rough sense of how much active care can accelerate the process.
Major aphthous ulcers are larger, deeper, and far less common. They can take weeks or even months to heal and sometimes leave scars. These larger sores are more likely to need professional treatment.
Signs a Mouth Sore Needs Medical Attention
Any mouth sore that lasts longer than two weeks without healing deserves a professional evaluation. Oral cancer can initially look like an ordinary sore, appearing as a persistent ulcer, a white or reddish patch, or a lump inside the mouth. Other warning signs include pain that spreads to the ear, difficulty swallowing or opening your mouth, loose teeth, and numbness in any part of the mouth or lip. A doctor or dentist will typically examine the area visually and, if anything looks unusual, take a small tissue sample for testing.
Unusually large sores that are slow to heal can also be associated with immune system conditions. Sores that keep coming back in clusters, spread rapidly, or come with fever are also worth getting checked out rather than managing at home.