Most mouth sores are canker sores, and they heal on their own within one to two weeks. But you don’t have to wait it out in pain. A combination of simple rinses, over-the-counter products, and smart food choices can reduce discomfort and speed up healing noticeably.
First, Figure Out What You’re Dealing With
The two most common mouth sores look and behave differently. Canker sores appear inside the mouth, usually on the inner cheeks, lips, or tongue. They’re round, white or yellow, and rimmed with red. They are not contagious and have no single known cause, though stress, minor injuries (like biting your cheek), smoking, and nutritional deficiencies can trigger them.
Cold sores (fever blisters) are different. They show up on the outside of the mouth, typically around the border of the lips, as clusters of small fluid-filled blisters. Cold sores are caused by herpes simplex virus type 1 and are contagious. If your sore is on the outside of your lips and started as a tingly blister, it’s likely a cold sore and may benefit from antiviral treatment rather than the remedies below. The rest of this article focuses primarily on canker sores and general inner-mouth sores.
Salt Water and Baking Soda Rinses
A salt water rinse is the fastest, cheapest thing you can do right now. It draws fluid out of the inflamed tissue, which reduces swelling, and it creates an environment that’s harder for bacteria to thrive in. Mix 1 teaspoon of table salt and 1 teaspoon of baking soda into 4 cups of warm water. Swish a mouthful gently for 30 seconds, then spit it out. Repeat every four to six hours throughout the day.
If you want more direct contact with the sore, make a thin paste of baking soda and a few drops of water and dab it onto the ulcer with a clean finger or cotton swab. It will sting briefly, then the alkaline environment helps neutralize acids that irritate the wound.
Over-the-Counter Pain Relief
When a rinse isn’t enough, topical numbing gels offer stronger relief. Products marketed for mouth sores typically contain 20% benzocaine, a local anesthetic that temporarily deadens the nerve endings around the ulcer. You apply a small amount directly to the sore with a clean fingertip or cotton swab. The numbness kicks in within a minute or two and lasts long enough to eat or drink more comfortably.
Look for gels specifically labeled for mouth sores rather than general toothache products, since the formulations are designed to stick to wet tissue. Some also contain zinc chloride and menthol, which provide a mild antiseptic and cooling effect. Avoid using these products more frequently than the label directs, as overuse of benzocaine can irritate the surrounding tissue.
Honey as a Healing Aid
Plain honey is more than a folk remedy. A clinical trial comparing honey to a prescription-strength topical steroid found that honey performed significantly better at reducing ulcer size, pain, and redness. Participants who applied honey healed faster than those using either the steroid or a protective paste alone.
To try this, dab a small amount of raw, unprocessed honey directly onto the sore three or four times a day. It forms a natural protective barrier, keeps the area moist, and has mild antibacterial properties. It will taste better than baking soda paste, which makes it an especially good option for children with canker sores.
Foods That Make Sores Worse
What you eat while a sore is healing matters almost as much as what you put on it. Certain foods create direct chemical or physical irritation that resets the healing clock.
- Citrus fruits like oranges and grapefruits contain acid that burns on contact with an open ulcer.
- Spicy foods irritate the entire area in and around your mouth, not just the sore itself.
- Salty snacks like chips and salted nuts cause a sharp burning sensation against raw tissue.
- Vinegar-based foods like pickles and some salad dressings sting for the same reason citrus does.
- Crunchy or sharp-edged foods like toast, crackers, and hard chips can physically scrape the sore and delay healing.
Stick to soft, cool, bland foods while your sore is active. Yogurt, smoothies, scrambled eggs, and lukewarm soups are all safe bets. Drinking through a straw can help liquids bypass a sore on your lip or the front of your mouth.
Why Some People Get Sores Repeatedly
If canker sores keep coming back, there may be an underlying nutritional gap. Deficiencies in iron, folic acid, vitamin B12, vitamin B3, and vitamin C have all been linked to recurrent mouth ulcers. Vitamin B12 deficiency in particular appears to suppress parts of the immune system and alter the cells lining the mouth, making them more vulnerable to breakdown. In documented cases, correcting a B12 deficiency eliminated recurring sores entirely.
Your toothpaste could also be a factor. A systematic review of clinical trials found that people who switched to toothpaste free of sodium lauryl sulfate (SLS), a common foaming agent, experienced significantly fewer ulcers, shorter episodes, and less pain compared to those using standard SLS-containing toothpaste. SLS-free options are widely available; check the ingredients list on the back of the tube. Brands that skip SLS often advertise it on the front label.
What a Normal Healing Timeline Looks Like
A typical minor canker sore peaks in pain around days two through four, then gradually shrinks. Most heal completely within one to two weeks without leaving a scar. During the first few days the sore may appear to get slightly larger before it starts to close, which is normal.
Major canker sores, which are larger than about a centimeter across, can take considerably longer and sometimes leave scarring. These are less common but significantly more painful.
Signs a Mouth Sore Needs Medical Attention
A sore that lasts longer than two weeks without improvement should be evaluated by a dentist or doctor. That timeline is the standard threshold recommended by Cleveland Clinic and other major medical centers, because persistent sores can occasionally signal something beyond a simple canker sore, including oral infections or, rarely, oral cancer. You should also seek evaluation if you develop a high fever alongside the sore, if sores appear in clusters of many at once, or if the pain is severe enough that you can’t eat or drink adequately.