A canker sore on the tongue typically heals on its own within one to three weeks, but the pain can make eating, drinking, and even talking miserable in the meantime. The good news: several home treatments and over-the-counter products can cut that discomfort significantly and help the sore heal faster. Here’s what actually works.
Numb the Pain Quickly
The fastest relief comes from topical numbing products containing benzocaine, which you can find at any pharmacy as gels, liquids, or patches designed for mouth sores. Apply the gel directly to the sore up to four times a day. The numbing effect kicks in within a minute or two and lasts long enough to eat a meal or get through a conversation. Don’t use these products for more than two consecutive days without checking with a doctor or dentist.
If you don’t have a numbing gel on hand, pressing a small ice chip directly against the sore provides temporary relief by dulling the nerve endings. This works especially well right before meals.
Saltwater and Baking Soda Rinses
A simple rinse is one of the most effective home remedies. Dissolve 1 teaspoon of baking soda in half a cup of warm water and swish it around your mouth for 30 seconds, then spit. You can also use a basic saltwater rinse at a similar ratio. These rinses reduce the acidity inside your mouth, which takes some of the sting out and creates a better environment for healing. Repeat several times a day, especially after meals.
Foods to Avoid While It Heals
What you eat matters more than you might expect. Acidic foods are the biggest culprits for prolonging pain and slowing healing. That means cutting back on citrus fruits and juices, tomatoes and tomato-based sauces, coffee, carbonated drinks, and strawberries. Spicy foods like curry, hot peppers, and salsa will inflame the sore and make it worse.
Texture matters too. Chips, pretzels, nuts, and seeds have rough or sharp edges that can scrape the sore and re-injure the tissue. Stick to soft, cool, or lukewarm foods while your tongue heals: yogurt, oatmeal, mashed potatoes, smoothies, scrambled eggs. If you’re going to eat something potentially irritating, doing a baking soda rinse afterward can help neutralize the acid.
Switch Your Toothpaste
Many common toothpastes contain sodium lauryl sulfate (SLS), a foaming agent that can irritate the lining of your mouth and may even trigger canker sores in people who are prone to them. If you get canker sores frequently, check your toothpaste’s ingredient list. Switching to an SLS-free toothpaste is a simple change that reduces irritation to existing sores and may help prevent new ones. Several major brands now make SLS-free versions that are easy to find at drugstores.
When a Canker Sore Won’t Go Away
Most canker sores are minor, meaning they’re smaller than a pea, and they heal within a few weeks without leaving a scar. But there are two less common types worth knowing about. Major canker sores are larger than one centimeter, extremely painful, and can take months to heal, sometimes leaving scars. Herpetiform canker sores appear as clusters of tiny pinpoint sores rather than a single ulcer, though they typically heal within about two weeks.
For major canker sores or sores that keep coming back, a dentist or doctor may prescribe a corticosteroid rinse or gel. These reduce inflammation and speed healing for stubborn or severe cases. Prescription-strength treatments are typically reserved for sores that don’t respond to the home care and OTC options described above.
Nutritional Gaps That Cause Recurring Sores
If you’re getting canker sores repeatedly, your body may be low on certain nutrients. Vitamin B12 deficiency is one of the most common nutritional triggers. Low levels of iron, zinc, and folate (vitamin B9) are also linked to recurrent outbreaks. Iron and zinc support immune function and wound healing, while folate plays a role in healthy cell division in the tissues lining your mouth.
You don’t necessarily need supplements. Eating more leafy greens, beans, fortified cereals, red meat, and shellfish can address most of these gaps. But if canker sores keep showing up despite good oral care and avoiding trigger foods, a simple blood test can check for deficiencies worth correcting.
Signs Something More Serious Is Going On
A canker sore that hasn’t healed after two weeks deserves a professional look. While canker sores are almost always harmless, a sore that lingers, changes shape, or keeps growing can occasionally signal something else, including oral cancer. Key differences to watch for:
- Duration: A typical canker sore resolves within a few weeks. One that persists beyond two weeks, or keeps changing without healing, needs evaluation.
- Pain pattern: Canker sores hurt from the start and gradually improve. Oral cancer often starts painless and becomes more painful over time, then doesn’t let up.
- Appearance changes: Red, white, or mottled patches around the sore, rough or crusty texture, or a lump beneath the surface are all reasons to get checked.
- Other symptoms: Swelling in your neck or jaw lasting more than two weeks, numbness in your tongue, unexplained weight loss, a persistent feeling of something stuck in your throat, or a sudden change in how your teeth fit together all warrant a visit.
Also worth flagging to a provider: canker sores that are more frequent, larger, or more severe than what you’ve experienced before, or sores accompanied by fever, swollen lymph nodes, or persistent fatigue. These patterns can point to immune system issues or other underlying conditions that are treatable once identified.