Most canker sores heal on their own within a few weeks, but you don’t have to wait it out in pain. A combination of simple home rinses, over-the-counter topical treatments, and avoiding certain irritants can significantly reduce discomfort and speed up the process. Here’s what actually works.
Salt Water and Baking Soda Rinses
The simplest and cheapest remedy is one you can make right now. Mix one teaspoon of salt and one teaspoon of baking soda into four cups (one quart) of water. Swish it around your mouth for 15 to 30 seconds, then spit. Do this every four to six hours. You can also use just salt or just baking soda if that’s what you have on hand, at the same ratio of one teaspoon per quart of water. Use lukewarm water, not hot or cold.
The salt draws fluid from the sore, which helps reduce swelling. The baking soda neutralizes acids in your mouth that irritate the open tissue. Neither will sting as badly as you might expect if the water is properly diluted. This rinse won’t make a canker sore vanish overnight, but it creates a cleaner environment that supports faster healing.
Over-the-Counter Numbing Gels
For pain relief, look for an oral gel or paste containing benzocaine. Products like Anbesol, Orabase, and Zilactin-B are widely available at pharmacies. These are local anesthetics: they numb the tissue on contact so you can eat, drink, and talk without wincing. Apply the gel directly to the sore as soon as you notice it forming, and follow the label directions for how often to reapply.
Another option is a hydrogen peroxide mouth rinse formulated for oral sores (like Orajel Antiseptic Mouth Sore Rinse). These help keep the area clean and may prevent secondary irritation from bacteria. The key with any OTC product is to start early. Treating a canker sore in its first day or two, when it’s still forming, tends to reduce how painful and large it becomes.
Honey as a Topical Treatment
Applying honey directly to a canker sore three times a day is a home remedy with some clinical backing. In studies on oral ulcers, honey performed comparably to medicated gels for reducing pain and ulcer size. One study on denture-related mouth ulcers found that honey relieved symptoms significantly earlier than salt water rinses alone, with no adverse effects reported.
Use plain, unprocessed honey. Dab a small amount onto the sore with a clean finger or cotton swab after meals. It forms a protective coating over the ulcer, which shields it from food and saliva acids. The results aren’t dramatic, but if you prefer a natural option or don’t have pharmacy products handy, it’s a reasonable choice.
What to Avoid While It Heals
What you stop doing matters as much as what you start doing. Acidic foods like tomatoes, citrus fruits, and vinegar-based dressings will sting and can slow healing. Spicy foods and anything with sharp edges (chips, crusty bread, hard pretzels) physically irritate the sore. Stick to softer, blander meals until the ulcer closes.
Check your toothpaste ingredients. Sodium lauryl sulfate (SLS), the foaming agent in most toothpastes, can aggravate canker sores in some people. If you get canker sores frequently, switching to an SLS-free toothpaste may reduce how often they come back. Several brands market SLS-free options specifically for sensitive mouths.
How Long Healing Takes
Minor canker sores, the kind most people get, are smaller than a pea and heal within a few weeks without scarring. Pain typically peaks in the first three to five days, then gradually fades as the sore shrinks.
Major canker sores are a different story. These are larger than one centimeter, extremely painful, and can take months to heal. They often leave scars. If you’re dealing with a sore that seems unusually large or deep, that’s worth noting, because it changes what treatment you might need.
When a Canker Sore Needs More Than Home Care
Most canker sores don’t need medical attention, but some do. Prescription options exist for severe cases, including steroid-based topical creams (like fluocinonide) that reduce inflammation more aggressively than anything available over the counter. A doctor or dentist can also rule out other conditions that mimic canker sores.
The signs that warrant a visit: a sore lasting longer than two weeks, sores that keep appearing before old ones finish healing, pain so severe that you can’t eat or drink adequately, sores that extend onto the outer lip border, or a high fever accompanying the sore. Any of these patterns suggest something beyond a routine canker sore.
Nutritional Gaps That Fuel Recurring Sores
If canker sores are a recurring problem for you, not just a once-a-year annoyance, your diet may be a factor. Deficiencies in zinc, iron, and B vitamins have all been linked to frequent outbreaks. Zinc deficiency in particular has shown up repeatedly in studies of people with chronic canker sores, and correcting the deficiency can reduce recurrence.
A daily multivitamin containing zinc and a B-complex supplement is a reasonable starting point. For iron, it’s better to get your levels tested first, since too much iron carries its own risks. If you’re eating a varied diet and still getting canker sores every month or two, a simple blood panel can identify whether a nutritional gap is driving the problem.