The good news is that canker sores usually get better on their own, typically within a week or two, per Dr. Palomo. Still, 10 days can feel like an eternity when your mouth is pulsating with a persistent sting, so you might want to consider these at-home treatments while you wait.
1. Stick to eating soft and bland foods.
Because spicy, acidic, and sharp foods can further inflame or injure your ulcer, Dr. Palomo recommends steering clear of things like buffalo wings, citrus fruits, tortilla chips, and pretzels. Instead, try to stick with soft and bland options like oatmeal, mild soups, mashed potatoes, and bananas, she says.
2. Use an over-the-counter numbing gel.
To manage the discomfort, you can consider turning to over-the-counter numbing gels or creams specifically designed to go inside your mouth, like Orajel or Kank-A. Both of these topical treatments contain benzocaine, an anesthetic that’ll desensitize the area quickly, per the Mayo Clinic. Keep in mind, though: These types of pain relievers aren’t a long-lasting solution, since the saliva in your mouth can dissolve them pretty quickly, Dr. Voigt cautions. Plus, benzocaine can sometimes cause allergic reactions, so you’ll want to be extra careful before going ham.
3. Gargle warm salt water.
A salt water rinse is one treatment many people (myself included) swear by—even though there isn’t much research to back it up. The idea behind this DIY solution: Salt (which has antibacterial properties) will reduce some of the inflammation that’s causing you so much pain.
If you’re considering giving this home remedy a try, the National Health Service (NHS) recommends using just half a teaspoon of salt and mixing it into a cup of warm water—then rinsing, gargling, and repeating twice a day. (Using too much salt or swishing too frequently, Dr. Palomo says, might cause more irritation.)
4. Use a cotton swab to apply milk of magnesia on your sore.
Milk of magnesia is a liquid antacid commonly used to treat heartburn and indigestion, but Dr. Palomo says applying a little bit on your sore can knock out some of that pain.
There’s no solid research showing that it actually gets rid of mouth ulcers (you know, since it’s meant to help with gastrointestinal issues). But Dr. Palomo explains that milk of magnesia will at least “create a little barrier around the sore”—it’s like giving that painful region a little shield so that it doesn’t get more irritated.
Just keep in mind that accidentally swallowing too much can cause unpleasant side effects like diarrhea, she adds, so if your sore lasts more than three weeks, see a primary care doctor—Dr. Palomo says milk of magnesia should only be used for short-term relief.
5. Cover the area with a mixture of alum and water.
Some people also apply alum, a pickling agent you can find at most grocery stores, for immediate relief. More specifically, it’s generally recommended to mix a bit of alum powder with a drop or two of water until a paste forms, apply it to your sore for a few minutes, then rinse thoroughly with water. (Alum is an astringent, so leaving it on for too long can be irritating and drying.)
