Most canker sores heal on their own within one to two weeks, but the right care can cut down pain significantly and speed that timeline along. These small, shallow ulcers inside your mouth aren’t contagious (they’re not cold sores), but they can make eating, drinking, and talking genuinely miserable. The good news: a combination of simple home remedies and over-the-counter products can make a real difference.
Salt Water and Baking Soda Rinses
The simplest and cheapest thing you can do is rinse your mouth several times a day. Dissolve one teaspoon of baking soda in half a cup of warm water and swish gently for 30 seconds before spitting. A salt water rinse works similarly: about half a teaspoon of table salt in the same amount of warm water. Both options help neutralize acids in your mouth and create a cleaner environment around the sore, which reduces irritation and supports healing.
Aim for three to four rinses a day, especially after meals. It will sting briefly on contact, but the relief afterward is noticeable. You can alternate between salt and baking soda rinses or stick with whichever feels more comfortable.
Over-the-Counter Pain Relief
Topical numbing products containing benzocaine (sold under brand names like Anbesol and Orajel) can temporarily block pain at the sore itself. You apply a small amount directly to the ulcer, and the numbing effect kicks in within a minute or two. These are especially useful right before meals, when chewing and contact with food would otherwise be painful.
Antiseptic mouth rinses containing chlorhexidine gluconate can reduce the severity and pain of ulcers, though they won’t prevent new ones from forming. Protective paste products that create a barrier over the sore (sometimes called oral adhesive pastes) serve a dual purpose: they shield the ulcer from friction and food contact while delivering medication that may shorten healing time. Look for products specifically marketed for canker sores rather than general oral care.
What to Eat and What to Avoid
What you put in your mouth matters a lot while a canker sore is active. Acidic foods like citrus fruits, tomatoes, and vinegar-based dressings directly irritate the open tissue and can intensify pain for hours. Spicy foods, salty snacks, and anything with rough or sharp edges (chips, crusty bread, raw vegetables) physically scrape against the sore and slow the healing process.
The Cleveland Clinic also identifies caffeine, eggs, cheese, peanuts, and almonds as potential triggers for some people. These don’t necessarily delay healing of an existing sore, but if you get canker sores frequently, tracking whether these foods precede your outbreaks can help you identify personal triggers. While you’re healing, stick to soft, cool, or room-temperature foods. Yogurt, smoothies, scrambled eggs (if they’re not a trigger for you), mashed potatoes, and oatmeal are all easy choices that won’t aggravate the sore.
Switch Your Toothpaste
This one surprises a lot of people. Sodium lauryl sulfate (SLS) is a foaming agent found in most mainstream toothpastes, and it’s been linked to canker sore recurrence. In three out of four clinical trials, people who switched to SLS-free toothpaste experienced a small but statistically significant reduction in how often they got canker sores. If you deal with recurring outbreaks, this is one of the easiest changes you can make. Check the ingredient list on your current toothpaste and look for SLS-free alternatives, which are widely available at most drugstores and grocery stores.
Zinc and Other Supplements
Zinc supplementation has shown promise for people who get canker sores repeatedly. A systematic review covering seven clinical trials and nearly 500 patients found that five of those studies showed significantly better results with zinc in reducing how often canker sores came back. The evidence isn’t unanimous (two studies found no significant difference), but the trend is encouraging enough to consider if you’re dealing with frequent recurrences.
Nutritional deficiencies in iron, folate, and vitamin B12 have also been associated with recurrent canker sores. If you get them often and can’t identify a clear trigger, it may be worth having your levels checked. Correcting a deficiency, if one exists, can sometimes reduce outbreaks substantially.
Prescription Options for Severe Cases
When over-the-counter remedies aren’t enough, prescription-strength treatments can help. Topical corticosteroids applied directly to the sore reduce the number of days you’re dealing with the ulcer and can meaningfully cut pain. They don’t prevent future sores from appearing, but they make the ones you have less severe and shorter-lived.
For people with frequent or unusually large sores, prescription oral adhesive medications offer another option. These combine a protective barrier with an active ingredient that reduces both pain and ulcer duration. Your doctor or dentist can determine which approach makes sense based on how often your sores appear, how large they get, and how well they respond to basic care.
Avoiding Common Triggers
Beyond food and toothpaste, several other factors can set off canker sores. Minor mouth injuries from aggressive brushing, dental work, or accidentally biting the inside of your cheek are among the most common. Using a soft-bristled toothbrush and being deliberate about not rushing through brushing can help. Stress is another well-established trigger, and while “reduce your stress” is easier said than done, it’s worth noting the connection if you notice outbreaks clustering around high-pressure periods in your life.
Hormonal changes, particularly around menstruation, trigger canker sores for some people. Others find that certain medications contribute. If you’ve recently started a new medication and notice an uptick in mouth sores, that’s worth mentioning to your prescriber.
When Canker Sores Need Attention
A typical canker sore is small (under a centimeter), painful but manageable, and gone within two weeks. Sores that are unusually large, spreading, lasting longer than three weeks, or accompanied by fever fall outside the normal range. The same goes for sores that are completely painless (which can indicate something other than a canker sore) or outbreaks so frequent that one sore barely heals before the next appears. Any of these patterns warrant a closer look from a doctor or dentist, who may want to rule out other conditions or start you on a more targeted treatment plan.