7 Ways to Get Rid of Canker Sores Fast (With Pictures)

Almost everyone has had a tiny sore in their mouth that made it painful to eat or talk. That annoying little ulcer was most likely a canker sore. Canker sores are one of the most common mouth conditions in the U.S. Almost everyone will have a canker sore at least once. And about 1 in 5 people will have them repeatedly over their lifetime.

Because canker sores are quite painful, many people look for quick at-home remedies to treat them. Let’s take a closer look at what canker sores are and what you can do to get rid of them quickly.

What are canker sores?

Canker sores (aphthous ulcers) are painful, white- or yellow-topped ulcers within the mouth. They can happen inside the cheeks, on the gums, or on the tongue. Most people only get one canker sore at a time. But some people get several at a time. 

Canker sores are defined by their size, number, and appearance. Canker sores can be:

• Minor: These canker sores are small. They’re usually just a few millimeters in size.

• Major: These canker sores are larger, about 1 cm to 3 cm in diameter.

• Herpetiform: These canker sores are made of many pinhead-sized ulcers bunched together.

What causes canker sores?

Even though canker sores are very common, healthcare professionals don’t really know what causes them. Some people get them frequently. Others never do. 

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Some of the triggers for canker sores include:

• Injury

• Stress

• Vitamin deficiency (like B12, folic acid, or iron)

• Smoking

• Food allergies

• Hormonal changes

• Viral infections

How to get rid of canker sores fast

Canker sores usually go away on their own in a few days. But there are over-the-counter (OTC) treatments that may speed up healing or lessen the pain. 

Here are seven ways you may be able to speed the healing of your canker sore.

1. Mild or salt water mouthrinse

Mild mouthrinses like salt water may help to heal your canker sore. Mouthrinses can decrease bacteria and inflammation in the mouth. If possible, rinse your mouth several times a day using salt water or a mild mouthwash. But you’ll want to be careful what you use. You’ll need to avoid using a mouthwash that contains alcohol. This can be irritating.

2. Hydrogen peroxide

Hydrogen peroxide can help to improve healing of your canker sore by keeping it clean. Hydrogen peroxide works as an antiseptic to decrease the amount of bacteria in and around the ulcer. You can apply a 50-50 mixture of hydrogen peroxide and water directly to the sore using a clean cotton swab.

3. Milk of magnesia

Milk of magnesia is commonly used for constipation. But it can also help with canker sore pain and reduce its healing time. It’s best used after first cleansing the canker sore with hydrogen peroxide. You can then follow with a dab of milk of magnesia applied directly on the canker sore.

4. Magic mouthwash

Magic mouthwash can help with the pain of a canker sore and can make it go away faster. But you’ll need a prescription for this one. 

This is usually a combination of antacid, antihistamine, and a local anesthetic. You don’t swallow the mixture. Rather, you typically gargle with it. Just swish it around in your mouth for about 1 minute, then spit it out.

5. Topical pain reliever

You can try an OTC pain reliever like benzocaine, which is typically found in products like Orajel or Anbesol. These work as a topical anesthetic. They don’t work to heal the canker sore. However, these gels can help you get through the tough first days when the inflammation and pain is high.

6. Cold, bland foods

Cold, bland foods may be easier to tolerate and less irritating when trying to get a canker sore to heal. As it turns out, spicy, salty, or abrasive foods can increase inflammation and prolong the healing time. 

7. Honey

Honey applied to a canker sore may speed up healing. Honey is known for its antibacterial and anti-inflammatory properties. So, it can work well as an at-home remedy to get rid of canker sores fast. Applying honey to your canker sore 4 times a day for 5 days can work to decrease pain, redness, and its size.

How long do canker sores typically last?

Canker sores will usually resolve on their own over time. They’ll typically run their course in about 2 weeks. Canker sores will typically follow a predictable pattern, like:

• Prodromal stage: This stage lasts 1 to 3 days. You might notice a tingling or burning sensation at the spot where the ulcer will erupt.

• Ulcer stage: This stage can last 3 to 6 days or longer. The ulcer is often very painful and sensitive at this stage.

• Healing stage: This stage can last a few days for minor ulcers. It can last a couple of weeks for major ulcers. Sometimes, major ulcers can leave scars as they heal. 

If a canker sore doesn’t heal within 2 to 3 weeks, or if there are many sores, talk to a healthcare professional to find out if something more serious is going on.

What does a canker sore look like?

People can sometimes mistake canker sores for other things, like fever blisters. But canker sores look different from cold sores (fever blisters). Fever blisters are very contagious and usually occur on or around the lips. Luckily, canker sores aren’t contagious. Also, they appear inside the mouth. 

Canker sores usually appear anywhere inside the mouth as round, white, or yellow sores with a red border. You can have one or multiple at the same time. Below are some pictures of canker sores in different locations.

Canker sore on the lower lip.

Several canker sores on the upper lip.

A large canker sore inside the mouth.

Several canker sores on the tongue.

Other signs of a canker sore include:

• A burning or tingling sensation at the site before the sore appears

• Swelling in the area around the sore

• Pain as the main symptom of a canker sore

There’s usually no fever with canker sores. If you do get a fever with your canker sore, there may be another condition causing your symptoms. 

How can you prevent canker sores?

There’s no sure way to prevent canker sores. But avoiding known triggers may keep you from having future episodes. If you have them repeatedly, you may also consider getting your vitamin levels checked. And you may want to have testing done for a food allergy.

Some people find it helpful to eliminate certain things from their diet, like spicy foods or gluten. Good oral hygiene is also important. Brushing with a soft bristle toothbrush and flossing regularly can minimize irritation that could lead to canker sores.

When should I see a doctor or dentist about canker sores?

Canker sores usually don’t have any other symptoms than pain and ulcers. Warning signs that should prompt you to see a healthcare professional include:

• Fever

• Blisters on the skin

• Eye redness

• Any kind of sore if you have a weakened immune system

• Trouble eating or drinking

• Feeling generally ill

• Sores lasting more than 10 days without improving 

That’s because not all ulcers in the mouth are simple canker sores. Rarely, ulcers in the mouth can be a sign of an infection or autoimmune or gastrointestinal disease. 

Medical conditions that can appear with mouth sores are:

• Behçet’s disease

• Stevens-Johnson syndrome

• Syphilis or gonorrhea

• Inflammatory bowel disease or celiac disease

• Oral cancer

• Oral candidiasis (thrush)

Frequently asked questions

Why trust our experts?

Written by:

Frank Schwalbe, MD

Frank Schwalbe, MD, is an assistant professor of anesthesiology at the Yale School of Medicine. He has practiced anesthesiology for 30 years.

Edited by:

Karla Robinson, MD

Karla Robinson, MD, is a medical editor for GoodRx. She is a licensed, board-certified family physician with almost 20 years of experience in health through varied clinical, administrative, and educational roles.

Reviewed by:

Maria Robinson, MD, MBA

Maria Robinson, MD, MBA, is a board-certified dermatologist and dermatopathologist who has practiced dermatology and dermatopathology for over 10 years across private practice, academic, and telehealth settings. She is a fellow of the American Academy of Dermatology and the American Society of Dermatopathology.

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