Most mouth sores heal on their own within one to two weeks, but you can speed up relief and reduce pain with a few proven strategies. The right approach depends on what type of sore you’re dealing with, since canker sores, cold sores, and irritation-related ulcers each respond to different treatments.
Identify What You’re Dealing With
The quickest way to tell canker sores from cold sores is location. Canker sores are painful white or yellow ulcers that form inside the mouth, on the inner cheeks, lips, or tongue. Cold sores (fever blisters) are fluid-filled blisters that appear outside the mouth, typically around the border of the lips. This distinction matters because cold sores are caused by the herpes simplex virus and may need antiviral treatment, while canker sores are not contagious and respond to different remedies.
You might also develop sores from biting the inside of your cheek, burns from hot food, braces rubbing against tissue, or irritation from ill-fitting dentures. These trauma-related sores usually heal fastest once the source of irritation is removed.
Home Remedies That Actually Help
A warm saltwater rinse is the simplest and most widely recommended first step. Mix about half a teaspoon of salt into a cup of warm water and swish it around your mouth for 30 seconds, two to three times a day. The salt draws fluid out of the inflamed tissue, which reduces swelling and creates a less hospitable environment for bacteria.
Baking soda works similarly. Mix a teaspoon into half a cup of warm water for a rinse, or make a paste with a few drops of water and dab it directly on the sore. Baking soda neutralizes acids in the mouth that can irritate open tissue. Honey applied directly to an ulcer can also ease pain and support healing, thanks to its natural antibacterial properties. Apply a small amount to the sore a few times daily.
Ice or cold foods like popsicles won’t speed healing, but they numb the area and make eating more tolerable. Avoiding spicy, acidic, or crunchy foods while you have a sore prevents further irritation and lets the tissue recover faster.
Over-the-Counter Pain Relief
If home remedies aren’t cutting it, topical oral pain relievers containing benzocaine (typically at 20% concentration) are widely available. Products like Orajel numb the sore on contact and provide temporary relief for canker sores, cold sores, and general mouth irritation. You apply the gel directly to the sore, and the numbing effect lasts long enough to eat or drink comfortably.
Hydrogen peroxide rinses (diluted to half strength with water) can also help clean the sore and reduce bacteria. Some people find antiseptic mouthwashes containing chlorhexidine helpful for reducing the severity and pain of ulcers, though these won’t prevent new ones from forming. Protective pastes that coat the sore and shield it from food and saliva are another option, especially for sores in spots that get constantly bumped by your teeth.
When You Need Something Stronger
For sores that are unusually large, extremely painful, or keep coming back, a doctor or dentist can prescribe topical steroid pastes. These reduce inflammation at the site and are the standard treatment for recurring canker sores. They typically shorten how long each ulcer lasts and reduce pain, though they don’t prevent future outbreaks. Prescription antimicrobial rinses can also help with pain and severity in stubborn cases.
For cold sores specifically, antiviral medications work best when started at the first sign of tingling, before the blister fully forms. If you get cold sores frequently, a doctor may prescribe antiviral medication to take at the onset of symptoms or even daily to reduce outbreaks.
Nutritional Deficiencies and Recurring Sores
If you keep getting mouth sores despite good oral hygiene, your diet may be a factor. Recurring ulcers are often linked to deficiencies in vitamin B12, folate, and iron. These nutrients support cell repair and tissue regeneration in the mouth. When levels are low, the lining of your mouth becomes more sensitive to irritation and slower to heal. A simple blood test can check these levels, and supplementation or dietary changes often reduce the frequency of outbreaks significantly.
Foods rich in B12 include meat, fish, eggs, and fortified cereals. Folate is found in leafy greens, beans, and citrus fruits. Iron comes from red meat, lentils, spinach, and fortified grains. If your sores are a recurring problem, addressing these potential gaps is one of the most effective long-term strategies.
Preventing Future Sores
Your toothpaste could be contributing to the problem. Many common toothpastes contain sodium lauryl sulfate (SLS), a foaming agent that can strip the delicate lining of your mouth. Research has shown that people prone to canker sores experience significantly fewer outbreaks when switching to an SLS-free toothpaste. One clinical study found four times fewer soft tissue lesions after using SLS-free toothpaste compared to one containing SLS. If you deal with frequent ulcers or notice your mouth peeling, look for toothpaste labeled SLS-free.
Other practical prevention steps include using a soft-bristled toothbrush to avoid scraping your gums and cheeks, managing stress (a well-known trigger for canker sores), staying hydrated, and being careful with hot or sharp foods. If braces or dental appliances are causing sores, orthodontic wax can create a barrier between the hardware and your tissue.
Signs a Mouth Sore Needs Medical Attention
A sore that lasts longer than two to three weeks without healing warrants a visit to your doctor or dentist, even if it doesn’t hurt. Painless sores that won’t heal are actually more concerning than painful ones. The Mayo Clinic lists these as potential signs of oral cancer: a lip or mouth sore that doesn’t heal, white or reddish patches inside the mouth, a lump or thickening in the cheek, unexplained mouth pain, ear pain, or difficulty swallowing. Any of these symptoms persisting beyond two weeks should be evaluated.
You should also seek care if you develop sores accompanied by high fever, if the sores are unusually large (bigger than a pencil eraser), if they spread rapidly, or if you’re having so much pain that you can’t eat or drink enough fluids. Multiple sores appearing simultaneously or sores that keep returning in clusters can sometimes signal an underlying immune issue worth investigating.