How long does it take to heal a canker sore

Q: Why is canker sore not going away?

Its possible that your canker sores arent random, but are a symptom of a larger underlying health issue or disease. Non-healing canker sores are often traced back to root causes such as autoimmune diseases, vitamin or mineral deficiencies, or allergies.

Knowing how to get rid of canker sores can help reduce pain and speed the healing process. There are various home remedies and over-the-counter (OTC) treatments for canker sores, such as:

Mouth rinses, like a saltwater or hydrogen peroxide rinse
Natural products, such as honey
OTC medicines, like Benadryl or milk of magnesia

When such remedies aren't enough, a prescription canker treatment like tetracycline may be needed.

This article will go over ways to get rid of canker sores. You'll also learn when to call your provider or dentist about a canker sore instead of trying to use home remedies.

Verywell / Brianna Gilmartin

What Are Canker Sores?

Canker sores are common ulcers in the mouth. They are usually small and shallow and form at the base of the gums. Cankers are also called aphthous ulcers.

Cankers usually start off with a tingling sensation but can become painful. Some people may hesitate to talk, eat, or drink because of the discomfort from a canker.

Click Play to Learn About the Potential Causes of Canker Sores

What Causes Canker Sores?

The exact cause of canker sores is unknown but there are some common triggers including:

Hurting your mouth or gums (e.g., having dental work, biting your cheek, or wearing dentures that don't fit well)
Irritating foods (e.g., acidic fruits and vegetables; coffee, chocolate) or food allergies
Vitamin deficiencies (e.g., vitamin B-12, folate, iron, and zinc)
Certain medications (e.g., some arthritis drugs, chemotherapy)
Hormonal fluctuations
Certain medical conditions (e.g., Celiac disease, Inflammatory bowel disease (IBD), Immunodeficiency disorders, Helicobacter pylori)
Stress

Are Cankers Contagious?

Canker sores are not contagious. You can't catch them from someone else or give them to someone else.

How Long Do 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 hurt less until they get better.

There are many OTC pastes, gels, and liquid treatments that can temporarily relieve pain and speed the healing of cankers. The options work best if you apply them directly to each canker sore as soon as it appears.

Your pharmacist, provider, or dentist can offer advice on which canker treatment is best for you.

Home Remedies for Cankers

Avoiding canker sore triggers is a good place to start. You can also try some home remedies to reduce pain and help the sores heal.

Salt Water and Sodium Bicarbonate

Saline (salt water) and sodium bicarbonate (baking soda) can help cankers 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.

How to Make a 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. It may sting at first.

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

How to Make a Baking Soda Paste

Mix a little 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

Hydrogen peroxide is an antiseptic that can help keep your sore free of bacteria, which will help it heal.

How to Make a Hydrogen Peroxide Rinse

Mix one part hydrogen peroxide with one part water. Dab the solution on your canker sore with a cotton swab.

If you're using a hydrogen peroxide solution to rinse your mouth, do not swallow it.

Honey

Studies have found that honey has healing properties, including for canker sores.

How to Use Honey

Applying honey to the sore several times a day can help reduce pain as well as decrease ulcer size and redness.

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

Coconut Oil

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

How to Rinse With Coconut Oil

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

Apple Cider Vinegar Rinse

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

How to Make an Apple Cider Vinegar Rinse

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.

An apple cider vinegar rinse may sting. You also don't want to use the rinse more than once a day because vinegar is highly acidic and can damage tooth enamel.

OTC Canker Treatments

You can find several non-prescription treatments for canker sores in the dental care section of your supermarket or drugstore.

Oral Health Products

Antiseptic mouth rinses contain ingredients that help heal mouth sores by reducing the bacteria in your mouth.
Oral care products that numb painful areas in the mouth are useful while you're waiting for a canker to heal.
Products marketed for mouth sores provide pain relief and support canker sore healing. These products come in gel, paste, and rinse forms.

Follow the manufacturer’s instructions when using OTC products. Do not use more than one OTC product at the same time or mix them with treatments that have been prescribed for you unless your pharmacist or provider says it's OK.

Milk of Magnesia and Benadryl

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

The best way to put milk of magnesia to a canker is with a cotton swab. You can apply it three to four times a day. You may want to put it on after rinsing your mouth with a hydrogen peroxide solution.

Liquid Benadryl (diphenhydramine), an allergy medication, can also help reduce inflammation and encourage the healing of a canker sore. Benadryl is very useful for mouth ulcers that are 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.

Prescription Treatments for Cankers

Prescription medication is sometimes necessary to treat persistent or infected canker sores.

One treatment your dentist can prescribe is tetracycline suspension (liquid). You will need to hold the medicine in your mouth for two to five minutes before swallowing it.

Tetracycline is usually not prescribed for children with canker sores because it can cause permanent discoloration in developing teeth.

Corticosteroids

Your dentist may prescribe corticosteroids like prednisone and dexamethasone for severe canker sores. Dexamethasone suspension (liquid) can be used as an oral rinse that you hold in your mouth, then spit out.

When to See a Dentist for a Canker Sore

If you have a canker sore that does not get better with home remedies or OTC treatment, you might need something else. It's important to be seen by a healthcare provider who can prescribe the right treatment.

Call your dentist if you have:

A canker sore that lasts for 14 days or longer
A sore that is getting worse
A canker sore that grows in size or is unusually large
Frequent outbreaks of canker sores
Extreme pain that you cannot control
Sores on your lips
Fever

Summary

You can reduce canker sore pain and support healing with some OTC and at-home remedies like salt water rinses, honey, and oral health products.

If you have many canker sores, they hurt a lot, or they keep coming back, it's time to see a dentist. They can find out why you have cankers and prescribe the best treatment for them.

Frequently Asked Questions

Will salt heal a canker sore?
Using salt on a canker sore will not help it heal and can be very painful. Instead, try using a salt water rinse and applying a baking soda paste to the sore. These mixtures make it harder for bacteria in your mouth to grow, which gives the sore a chance to heal.
What is the best treatment for a canker sore on the tongue?
The fastest and best way to treat a canker sore on the tongue is usually with an OTC oral care product. You can get them as a gel, paste, or rinse at your local pharmacy or grocery store in the dental care section.
Does Listerine help canker sores?
Using a mouthwash like Listerine that has alcohol in it can irritate sores or sensitive areas in your mouth.
Can kids get canker sores?
Kids can get cankers just like adults can. They can be caused by the same triggers, such as allergies, nutritional deficiencies, or poor oral hygiene.
You can help a child with a canker sore by having them swish with salt water (just make sure they don't swallow it) and use OTC products to ease discomfort while the mouth is healing. If your child gets cankers often, let their dentist know.

What is the fastest way to heal a canker sore?

Use salt water or baking soda rinse (dissolve 1 teaspoon of baking soda in 1/2 cup warm water). Dab a small amount of milk of magnesia on your canker sore a few times a day. Avoid abrasive, acidic or spicy foods that can cause further irritation and pain.

How do you know a canker sore is healing?

In the next stage, the typical yellow-gray ulcer forms, with redness surrounding the ulcer like a halo. During this period, the pain may increase. Finally, the healing stage begins, and healthy tissue starts closing over the sore. The pain goes away as the ulcer gets smaller.

Can a canker sore go away in 2 days?

Most canker sores will heal on their own in a few days to a couple of weeks.

Why is canker sore not going away?

It's possible that your canker sores aren't random, but are a symptom of a larger underlying health issue or disease. Non-healing canker sores are often traced back to root causes such as autoimmune diseases, vitamin or mineral deficiencies, or allergies.