Home Remedies for Canker Sores

By Zina Semenovskaya, MD
Medically reviewed checkmarkMedically reviewed
August 11, 2022

Canker sores are common mouth sores, and while they typically resolve on their own, they are uncomfortable and can make it challenging to eat and drink normally. 

There are many home remedies that can help canker sores, including salt water rinses, yogurt, special mouthwash, and more.

In this guide, we’ll explore home remedies for canker sores, common causes and symptoms, and how to know when you should see a physician or dentist for further treatment.

Home Remedies for Canker Sores

No home treatments will get rid of a canker sore immediately, but they can help to decrease pain and let them heal faster.

Alum powder

Alum powder comes from potassium aluminum sulfate, an ingredient that is frequently used to pickle vegetables and preserve foods.

It has properties that may help shrink canker sores and dry them out, helping them clear up more quickly.

Make a paste with alum powder by combining a small amount with a drop of water. Dab the paste onto the canker sore using a clean finger or a cotton Q-tip. 

Let the paste sit for at least one minute before rinsing your mouth thoroughly with water. Repeat every day until the canker sore is gone.

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Salt water rinse

Salt water is a healing remedy for many types of mouth sores. It can help dry out canker sores, although it may temporarily cause pain when applied to the sore.

If you can manage to sit through the discomfort, it may work quickly.

To make an effective salt water rinse, dissolve a teaspoon of salt into a half cup of warm water. Swish it around the mouth for 30 seconds and then spit it out.

Repeat every 2-3 hours until the canker sore is gone.

Baking soda rinse

Baking soda has a pH-balancing effect. It can help to reduce inflammation in the mouth and help canker sores heal more quickly.

Dissolve a teaspoon of baking soda in a half cup of warm water.

Swish the mixture around in your mouth for 30 seconds and then spit it out. Repeat every 2-3 hours as needed until the canker sore is gone.

Yogurt

Yogurt may help canker sores in a few ways.

First, it can coat the mouth and may help to alleviate surface discomfort.

Second, while it’s not definitively established, some researchers think that canker sores can be caused or worsened by certain types of bacteria. 

Animal research has shown that Lactobacillus, a common strain of probiotics found in yogurt, can help to get rid of H. pylori, a type of bacteria that may be in the oral cavity or digestive tract.

While research isn’t definitive, yogurt has other benefits, like high calcium content.

Try consuming a cup of yogurt daily while you have a canker sore to see if it helps and be sure to choose a low-sugar option that has live and active cultures.

Honey

Honey has antibacterial properties and may help to reduce canker sore size and pain. It may also help to prevent additional oral infections. 

Manuka honey, which is not pasteurized, has been shown to have more healing properties.

Apply the honey directly to the sore up to 4 times each day until it is gone.

Coconut oil

Coconut oil contains lauric acid, which gives it antimicrobial properties.

Apply it directly to the canker sore as many times per day as needed for relief until the canker sore is gone. 

Be sure to get a coconut oil that is intended for food preparation, since some products are meant for topical use only.

Hydrogen peroxide

Hydrogen peroxide is a common  ingredient in first aid products that can cleanse wounds and kill bacteria.

Mix a 3% solution of hydrogen peroxide with equal parts of filtered water.

Dip a cotton swab into the mixture and apply directly to the canker sore 2-3 times per day. 

Hydrogen peroxide can be diluted further to be used as a mouthwash, but take care not to swallow it.

Some OTC products meant for canker sores contain hydrogen peroxide and can also be used.

Milk of magnesia

Milk of magnesia is an osmotic laxative that can neutralize acid in the mouth. It contains magnesium hydroxide which can coat the sore to prevent irritation, relieve pain, and allow it to heal.

Using a clean finger or a cotton swab, apply a small amount of milk of magnesia directly onto the canker sore. Let it sit for 15-30 seconds and then rinse the mouth.

Repeat up to 3 times per day until the sore heals.

Chamomile compress

Chamomile is a natural remedy that can be used to soothe canker sores.

Apply a steeped chamomile tea bag to the canker sore for a few minutes. 

Make sure that it is not steaming hot to avoid burning mouth tissues.

You can also swish chamomile tea in the mouth several times a day until the sore heals.

Echinacea

Echinacea is a popular immune-boosting herb.

It can be used topically to promote healing in canker sores. Mix a teaspoon of liquid echinacea with equal parts warm (not hot) water. 

Swish the mixture in the mouth for 1-2 minutes. Spit out or swallow.

You can also use brewed echinacea tea as a mouthwash up to 3 times per day until the sore is gone.

Ice

Much like icing an injury can provide relief, using ice on canker sores can help ease pain, inflammation, and swelling in the mouth. 

You can suck on ice chips to provide short-term relief from pain, but ice won’t speed the healing process.

Sage

Sage is an herb that has medicinal properties. It can be used as an oral rinse for canker sores by making sage tea. 

Boil water and add 1-2 teaspoons of fresh sage leaves.

Let it steep for at least 5 minutes. Allow the liquid to cool, and then swish it inside your mouth for 1-2 minutes a few times per day until the canker sore is gone.

DGL mouthwash

Deglycyrrhizinated licorice (DGL) is an herbal extract that is used to address inflammation associated with stomach ulcers.

It may also have benefits for oral ulcers that are caused by canker sores.

DGL is available in capsule form as an herbal supplement.

Open a capsule and mix into a cup of warm water. Swish the solution in the mouth for 2-3 minutes and then spit it out. Repeat 2 times per day until the sore is healed.

It’s also available as an oral patch to treat canker sores. Apply a patch to the sore and leave on for 30 minutes.

Watermelon frost

Watermelon frost is an herbal medicine that is commonly used in traditional Chinese medicine (TCM). It can treat canker sores in the mouth. Apply the herbal powder or spray directly to the sore a few times per day until the sore is healed.

Apple cider vinegar rinse

Apple cider vinegar, sometimes called ACV, is reportedly good at curing many things. While there is not a lot of evidence behind some of these cures, ACV is generally harmless. 

Some people may find relief when using ACV for canker sores, while others feel that it is acidic and makes the pain worse.

If you want to try ACV for canker sores, combine a teaspoon of it with 1 cup of warm water. Swish in the mouth for 30-60 seconds. Spit out and rinse the mouth. Repeat daily as needed.

Zinc

Zinc is a mineral that supports normal immune function and wound healing.

Zinc lozenges may help get rid of oral bacteria that worsen mouth sores as well as support overall immune health.

You can find zinc lozenges in most pharmacies or health food stores. Follow the usage instructions on how many to use per day.

Vitamin B

Canker sores can sometimes be recurring if your body is low in vitamin B12 or other B complex nutrients. Supplementing with a B vitamin may help to prevent sores, but is unlikely to help them heal faster.

Over-the-counter topical gels

There are many OTC canker sore gels and creams that are designed to numb pain, reduce swelling, and provide relief while sores heal. 

The active ingredients in these products are usually benzocaine or lidocaine, both of which are pain relievers.

Follow the product’s usage guidelines. Most are meant to be applied directly to the sore for relief.

Over-the-counter treatments for canker sores may also include mouthwashes or special oral tablets meant to decrease dry mouth, which can worsen canker sores or make them take longer to heal.

What are Canker Sores?

Canker sores are small, round sores that form in the mouth. Medically they are known as aphthous stomatitis

They can flare up on the cheeks, under the tongue, on the lips, at the back of the throat, or on the soft tissue behind the hard palate (roof of the mouth).

Canker sores appear red on the edges and may look gray, white, or yellow at the center.

Sometimes they are too small to notice a color at the center, while other times they can be as large as a few centimeters. They may also appear individually or in clusters.

Canker sores are not contagious. It is not possible to spread them around to other parts of your mouth or body or to give them to anyone else.

Symptoms

Canker sores may cause the following symptoms:

  • Small sore on inside of the mouth
  • Red edge with a gray, white, or yellow ulcerated center
  • Can range from very small to a few centimeters large
  • May be mildly painful to severe enough to make it hard to eat or drink
  • Typically heal on their own within 1-2 weeks 

Causes

Canker sores are not completely understood, but seem to be caused or affected by the following factors:

  • Irritation from dental work
  • Vitamin or mineral deficiencies
  • Hormone changes (pregnancy, menstruation, menopause)
  • Food allergy exposure
  • Stress
  • Reduced immunity from HIV, AIDS, or cancer treatments
  • Autoimmune conditions
  • Celiac disease
  • During or after other viral or bacterial infections
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When to Seek Medical Attention for Canker Sores

Canker sores typically heal on their own and do not cause complications.

If you notice any of the following, you should consult a medical provider:

  • Canker sore that is larger than 2-3 centimeters
  • Multiple sores
  • New sores that form before other sores are gone
  • Sores that take longer than 2 weeks to heal
  • Sores cause extreme pain that prevent you from eating or drinking normally
  • You develop a fever or chills, or otherwise feel ill

For larger or harder to treat canker sores, a doctor or medical provider can prescribe steroids or antibiotics to help clear the infection. In some cases, what you think is a canker sore may be a mouth ulcer of a different kind, requiring a different kind of treatment.

Frequently Asked Questions

What gets rid of canker sores fast?
Canker sores take time to heal and won’t go away overnight. But OTC creams, gels, or mouthwashes can help to numb the pain and reduce inflammation so that they heal faster.
How do you get rid of canker sores overnight?
Canker sores won’t go away overnight, but using topical creams, gels, or mouthwashes can help to numb pain and help them get better faster.
How do you get rid of a canker sore in 5 minutes?
Using a medicated mouthwash or other home remedies for canker sores can help them to heal faster. Most sores heal on their own in 1-2 weeks without any treatment. Home remedies or OTC medicines can help them get better more quickly.
Does putting salt on a canker sore help?
Salt can be extremely painful on a canker sore, but swishing with salt water every 2-3 hours can help canker sores heal more quickly.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.

Zina Semenovskaya, MD

Dr. Semenovskaya specializes in emergency medicine, and received her medical degree from Weill Cornell Medical College. She is currently the medical director at Remote Emergency Medicine Consulting, LLC and splits her time working clinically as an emergency medicine attending in California and Alaska. She is the first of our doctors to be fluent in Russian.

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