Key takeaways:
Canker sores form inside your mouth. They can burn, tingle, and cause irritation.
They most commonly develop on the inside of the lips, cheeks, or gums.
Some people find relief by switching their toothpastes and mouthwash.
Have you ever felt one of those sores on the inside of your mouth that makes it painful to talk or eat?
It’s likely a canker sore. Small and shallow, canker sores are little lesions that form on the soft tissue in your mouth or gum line. The good news is they aren’t contagious. The bad news is they can make talking or eating pretty painful.
Most canker sores — also called mouth ulcers or aphthous ulcers — are round, whitish, or yellowish-red inflamed spots that often form inside your lip, cheeks, and gums. You might feel a slight burning or tingling sensation a few days before the sore appears. They usually heal within 10 days. But if a sore hasn’t healed within 2 weeks, it’s a good idea to see a healthcare provider.
Those who have experienced canker sores tell GoodRx they’ve tried everything from antimicrobial mouthwash to saltwater to try to get a canker sore to go away. Here’s how three people got rid of them.
Avoiding gluten helped
Holly Kelsey-Henry, a 61-year-old writer who lives near Duluth, Minnesota, says she has struggled with canker sores from an early age.
“I had them often as a kid and through college as well. They felt like little ulcers in my mouth,” she says. “Back then, there wasn't much you could do for them other than wait it out.”
Although her mother took her to a doctor for them as a child, nothing did much good.
“They would last about a week. I’d get them at least once a month,” she says. “They were very uncomfortable. I’d mostly get them under my tongue, sometimes on the inside of my cheeks. They were white ulcer-like things surrounded by angry red circles.”
After college, a digestive issue led to some relief, she says.
Read more like this
Explore these related articles, suggested for readers like you.
“In my 20s, I started having digestive problems,” she says. “I started eliminating certain foods to see if it would help. I felt better when not eating gluten, so I stuck with it. I never got another canker sore. With that said, if I do ingest some wheat before I realize it, I can almost immediately feel a tingling in my mouth. I can only attribute my case of canker sores to some kind of gluten intolerance.”
Tips to shorten a canker sore’s lifespan
Emily Parker, a 38-year-old blogger and mother of four from Georgia, has also struggled with canker sores for a long time. She says her canker sores may be brought on by a combination of stress and lack of sleep.
“I have struggled with canker sores from a very young age,” she says. “I’ve asked my doctors and dentists countless times for help regarding prevention and treatment.”
One part of her treatments, she says, is Prevention Mouth Rinse, an oral antiseptic that does not contain fluoride, alcohol, or dyes. Its active ingredient is hydrogen peroxide, coupled with sodium citrate, zinc, and glycerin.
A dental hygienist recommended she also take 1,000 mg of Lysine, an amino acid. And lastly, she says she mixes baking soda with a bit of water and applies the paste directly to the canker sore. All of those treatments help to not only minimize the pain, but shorten the canker sore’s lifespan, Emily says.
“The last time I had a canker sore, I did these three things and the sore only lasted 4 days, which is a massive improvement from the typical weeks of constant pain I normally experience,” she says.
Changing toothpastes solved his canker sore problem
For 32-year-old Daniel Caughill of New York City, the solution to treating his canker sores was simple — changing toothpaste. Daniel, founder of a resource website for dog owners, says he experienced canker sores for most of his life, especially when he ate spicy foods. A few years ago, they were happening almost every month.
“Around 3 or 4 years ago, I noticed them occurring more frequently, every 2 or 3 weeks, for a week at a time. They were incredibly painful, so that’s when I started looking more seriously for a solution,” he says.
Daniel found that sodium lauryl sulfate (SLS) was a foaming agent that contributed to canker sores. So he switched to a toothpaste without the SLS ingredient. Soon after, Daniel says that the sores calmed down for many months.
Now, he says, the canker sores aren’t as frequent.
“I still get them rarely, possibly from one of the other causes, such as after accidentally biting my tongue,” he says. “But sticking to an SLS-free toothpaste has pretty much solved the problem for me. I’m so grateful, because trying new foods and restaurants is one of my favorite things to do. And it’s hard to enjoy when every bite is painful.”
What does the doctor say?
Patricia Pinto-Garcia, MD, MPH
Medical Editor
Canker sores — or recurrent, simple aphthous ulcers — affect about 1 in 5 adults in the U.S. They are exquisitely painful and seem to pop up at the worst times. It’s not clear why some people develop canker sores, but several things can trigger them, especially:
Mouth trauma, like biting the inside of your cheek or dental cleanings
Spicy foods
Vitamin deficiencies, especially vitamin B12, zinc, or iron deficiency
Oral products with SLS
There’s no cure for canker sores, but treatment can make you more comfortable. And some prescription options — like steroid gels — can help your canker sores heal faster.
Lidocaine gel is one of the best options for pain control but is only available by prescription. If you’re looking for over-the-counter options, you can try dyclonine lozenges (Cepacol).
You can also try liquids that can coat your ulcers and relieve pain. Popular options include Benadryl and aluminum hydroxide, magnesium hydroxide, and simethicone suspension (Mylanta). Just make sure you don’t swallow these; the goal is to swish about 5 mL (1 teaspoon) around in your mouth and then spit it out.
You can read about other canker sore treatment options, including natural remedies and prescription options, in our GoodRx Canker Sore Treatment Guide.
Getting a canker sore once in a while isn’t a sign of a health condition. But if you get canker sores often or you get several at once, talk to your healthcare provider. Canker sores can be an early sign of autoimmune conditions like:
Why trust our experts?
