How to Get Rid of Canker Sores

Simple canker sores, also called aphthous ulcers, are among the most common ulcers in the mouth. They are usually small and shallow, and develop inside the mouth and at the base of the gums.

While they start off causing a tingling sensation, they can progress to become quite painful. Some people may hesitate to talk, eat, or drink because of the discomfort.

Home remedies and over-the-counter (OTC) treatments may help reduce pain and speed the healing process. When that’s not enough, a prescription may be needed.

This article outlines some commonly used options and when you should contact your dentist.

At-home and OTC canker sore remedies

Verywell / Brianna Gilmartin

How Long Canker Sores Last

Canker sores usually heal on their own within a week or two. Home remedies may reduce inflammation and bacteria, which can make the sores more bearable until they resolve.

Various OTC pastes, gels, and liquid treatments can also help temporarily relieve pain and speed healing. These work best if you apply them directly to each canker sore as soon as it appears.

Your pharmacist, doctor, or dentist can offer advice on which may work best for you.

Home Remedies

The exact cause of canker sores is unknown, but triggers may include stress and minor injury inside the mouth. In addition, some foods, such as acidic fruits and vegetables, or medicines can provoke canker sores or make existing ones worse.

Obviously, managing any possible triggers is a good place to start. Beyond that, you can try starting with some home remedies to reduce pain and help healing along.

Salt Water and Sodium Bicarbonate 

Saline (salt water) and sodium bicarbonate (baking soda) can help canker sores heal faster by reducing acid levels in your mouth. This creates an environment that makes it harder for bacteria to grow, which can help the healing process. Saltwater rinses can also promote healthy gums. 

Salt Water Rinse

Never put salt directly on an ulcer. Instead, make a saltwater solution by mixing one teaspoon of salt in one cup of warm water. Swish it in your mouth or gargle it for about 30 seconds, then spit it out. Though it may sting at first, the benefits are worth it.

Putting salt directly on a canker sore can make it worse. Instead, make a saltwater solution and gently rinse your mouth with it.

Baking Soda Paste

Mix baking soda with a small amount of water until it thickens. Put the paste on your canker sore(s). Repeat as often as needed while your mouth heals.

Hydrogen Peroxide Solution

As an antiseptic, hydrogen peroxide can help keep your sore free of bacteria, which will help it heal.

Mix one part hydrogen peroxide with one part water. Dab the solution on your canker sore with a cotton swab. Never swallow the hydrogen peroxide solution.


Some studies have found that honey has healing properties for canker sores. Applying honey to each sore several times a day can help reduce the number of days of pain and ulcer size and redness.

You can also use honey as a canker sore remedy by mixing it in tea, such as chamomile, and drinking several cups throughout the day. Studies have found that chamomile is helpful by itself.

Coconut Oil

Coconut oil contains lauric acid, which can help fight some harmful bacteria in the body.

Daily swishing with about a tablespoon of this oil, a practice known as oil pulling, may help reduce bacteria in the mouth and aid the healing process. 

Alum Powder

Alum powder (crystallized potassium aluminum sulfate) is a food additive often used to help keep pickled fruits and vegetables fresh. It is also an ingredient in baking powder. You can buy it in the spice section of your grocery store.

Research has shown that alum can decrease canker sore size and reduce pain.

To use alum, create a paste by mixing a pea-sized drop with a drop of water. Then, apply the mixture directly to each canker sore and let it sit for at least one minute before rinsing with water. Do this daily until you see results.

Apple Cider Vinegar Rinse

Another antibacterial household staple, apple cider vinegar, can be used in a rinse to help heal your canker sores.

Mix a teaspoon of the vinegar into a cup of water. Swish the solution around your mouth for up to a minute. Then spit and rinse your mouth thoroughly.

Keep in mind that an apple cider vinegar rinse may sting. If it causes pain, you may want to try a different remedy. In addition, vinegar is highly acidic and can damage tooth enamel, so it’s best to use this just once a day.


Various items you may have as close as your pantry may help speed canker sore healing, fight oral bacteria, and reduce acid levels in the mouth. Salt water, coconut oil, apple cider vinegar can be used as rinses. Baking soda, hydrogen peroxide, and alum powder (all mixed with water) and honey can be applied directly to sores.

OTC Treatments

The dental care section of your supermarket or drugstore has several non-prescription options you can consider as well. Perhaps surprisingly, you might also benefit from using two medications actually intended for entirely other uses.

Oral Health Products

  • Antiseptic mouth rinses contain ingredients intended to help heal mouth sores by reducing the number of bacteria in the mouth.
  • Oral care products that numb painful areas in the mouth are also useful when treating canker sores.
  • Products marketed explicitly for mouth sores may provide pain relief and help speed the healing process. These come in gel, paste, and rinse forms.

It is essential to follow the manufacturers’ instructions closely when using OTC products.

Milk of Magnesia and Antihistamine

Milk of magnesia is a liquid suspension of magnesium hydroxide. It is frequently used as an antacid and to relieve constipation. It can also help reduce canker sore pain by neutralizing acid and coating the ulcer.

The best way to apply milk of magnesia to your canker sore is to use a cotton swab. You can apply it three to four times a day. Some people apply it after rinsing with a hydrogen peroxide solution.

Liquid Benadryl (diphenhydramine), an allergy medication, can help reduce inflammation and encourage healing. It may be particularly useful for mouth ulcers caused by food allergies or sensitivities.

You can combine liquid Benadryl with milk of magnesia to make an oral rinse. Mix one part of each and rinse with the solution for one minute, then spit it out. Do not swallow it.


Various over-the-counter oral health products—from gels to rinses to pastes—can help keep your mouth clean and dull pain. Milk of magnesia and a liquid antihistamine can also be mixed to form a rinse that can help healing as well.

Prescription Medications

Prescription medication may be necessary for treating persistent and/or severe canker sores that have gotten infected.

Your dentist may prescribe tetracycline suspension (liquid) and advise you to hold the medicine in the mouth for two to five minutes before swallowing it. Tetracycline is typically not prescribed for children as it can cause permanent discoloration in developing teeth.


In rare cases, your dentist could also prescribe corticosteroids like prednisone and dexamethasone. Dexamethasone suspension (liquid) as an oral rinse should be thoroughly spit out after a certain amount of time.


Prescription medications like tetracycline or corticosteroid may be used to treat canker sores that are severe or persistent.

When to See a Dentist

If you have a canker sore that doesn’t respond to home remedies or OTC treatment, it may be time to seek additional help and get a prescription.

Call your dentist if you have:

  • A canker sore last for 14 days or longer
  • A sore that seems to be getting worse
  • A canker sore that grows in size or is unusually large
  • Frequent outbreaks of canker sores
  • Extreme pain that you can't control at home
  • Sores on the lips
  • Fever

Early evaluation can not only help you ease your canker sore discomfort sooner, but it can help catch a budding infection, if present.


You can reduce canker sore pain and speed healing with some OTC and at-home remedies. Examples include salt water rinses, applying honey to sores, and oral health products like gels and rinses.

If you have many canker sores, they are extremely painful, or they recur frequently, see your dentist for advice. They may offer stronger, prescription medications and can evaluate you for a possible worsening infection.

Frequently Asked Questions

  • Will salt heal a canker sore?

    No, using salt on a canker sore will not help it heal and may instead be painful. Instead, try using a saltwater rinse and applying a baking soda paste to the sore. These mixtures make it harder for bacteria in your mouth to grow, which helps the canker sore heal.

  • What is the best treatment for a canker sore on the tongue?

    The best and potentially fastest treatment for a canker sore found on the tongue may be an over-the-counter oral care product. These can reduce pain and help the mouth heal. They come in three forms: a gel, paste, and rinse form. You can find these options at your local pharmacy or grocery in the dental care section.

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