Most canker sores heal on their own within two weeks, but the right combination of home care and over-the-counter products can cut down pain and speed that timeline. The key is reducing irritation, keeping the area clean, and addressing any underlying triggers that cause sores to keep coming back.
Salt Water and Baking Soda Rinses
The simplest and cheapest remedy is a mouth rinse you can make at home. Dissolve one teaspoon of baking soda in half a cup of warm water and swish it around your mouth several times a day, especially after meals. A salt water rinse (about half a teaspoon of salt in a cup of warm water) works similarly. Both options help clean the ulcer, reduce bacteria around the wound, and create an environment that supports faster healing. The sting lasts a few seconds, then the area usually feels calmer.
Over-the-Counter Pain Relief
Topical gels and pastes containing a numbing agent (like benzocaine) are the most common pharmacy option. You apply them directly to the sore, and they create a temporary barrier that dulls pain and protects the ulcer from food and saliva. Look for products specifically labeled for canker sores or mouth ulcers. Applying the gel after drying the area with a tissue helps it stick better and last longer.
Over-the-counter anti-inflammatory pain relievers taken by mouth can also help if the sore is making it hard to eat or talk. These won’t speed healing directly, but they reduce the inflammation that drives most of the discomfort.
Foods to Avoid While Healing
What you eat matters more than most people realize. Acidic foods like oranges, grapefruit, pineapple, and coffee directly irritate the exposed tissue and can make pain significantly worse. Spicy foods do the same. Salty, crunchy items like chips and pretzels can physically scrape the sore, reopening the wound and resetting the healing clock. Strawberries, chocolate, and cheese are also known triggers for some people.
Stick to soft, bland foods while a sore is active. Yogurt, oatmeal, scrambled eggs, and smoothies are easy choices. Drinking through a straw can help liquids bypass the sore if it’s on the inside of your lip or cheek.
Nutritional Gaps That Cause Recurring Sores
If you get canker sores frequently, a nutritional deficiency may be driving them. Low levels of vitamin B12, iron, zinc, and folate are all associated with recurrent outbreaks. A randomized, double-blind trial published in the Journal of the American Board of Family Medicine found that taking 1,000 micrograms of sublingual vitamin B12 daily for six months significantly reduced the number and duration of canker sores, regardless of whether participants were deficient in B12 at the start of the study. The tablets were taken once a day before bed.
This doesn’t mean B12 will help every single person, but if you’re dealing with sores that come back every few weeks, it’s worth asking your doctor to check your B12, iron, and folate levels. Correcting a deficiency can sometimes eliminate recurrences entirely.
Prescription Options for Severe Cases
Minor canker sores (under about a centimeter across) heal within a few weeks without scarring. Major canker sores, which are larger and deeper, can take months to heal and sometimes leave scars. If you’re dealing with major sores, or clusters that keep returning, a doctor can prescribe stronger treatments.
The most common prescription approach is a steroid mouth rinse, which reduces the immune response driving the ulcer and speeds healing. For severe, recurrent cases, a doctor may also prescribe an antimicrobial mouthwash combined with a short course of oral steroids at the first sign of an outbreak. These interventions work best when started early, during the tingling or burning phase before the ulcer fully forms.
Habits That Help Sores Heal Faster
Beyond specific treatments, a few everyday habits make a real difference. Use a soft-bristled toothbrush to avoid scraping the sore. Switch to a toothpaste free of sodium lauryl sulfate (SLS), a foaming agent found in most toothpastes that irritates mouth tissue and is linked to more frequent outbreaks in some people. Avoid chewing gum while a sore is active, since repeated contact with the ulcer slows healing.
Stress is one of the most consistent triggers. Many people notice sores appearing during exams, deadlines, or periods of poor sleep. You can’t always eliminate stress, but recognizing the connection helps you act early. Starting rinses and protective gels at the first tingle, before a full ulcer develops, can make the episode shorter and less painful.
When a Sore Needs Medical Attention
A typical canker sore hurts for a few days, then gradually fades over one to two weeks. If a sore hasn’t healed after two weeks, is getting worse instead of better, or looks unusual, it’s worth getting it checked. Warning signs include red, white, or mottled patches around the sore, a bump or lump under the skin, bleeding that won’t stop, rough or crusty texture changes, or visible swelling in your neck, cheek, or jaw. These don’t automatically mean something serious, but they overlap with signs of oral conditions that need professional evaluation. A sore that simply won’t resolve is the single most important reason to make an appointment.