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Canker sore treatment and medications

Cropped SingleCare logo By | Updated on April 26, 2020
Medically reviewed by Jeff Fortner, Pharm.D.

What is a canker sore? | Canker sore diagnosis | Canker sore treatment options | Canker sore medications | Best canker sores medications | Side effects of canker sores | Canker sores home remedies | FAQ | Resources

Having an open, painful sore in your mouth might mean that you have a canker sore. Canker sores can be difficult and frustrating to deal with. Understanding what canker sores are is an important first step toward treating them. This article gives an overview of canker sore treatments, medications, and home remedies.

What is a canker sore?

Canker sores are small ulcers that develop inside the mouth or at the base of the gums. Because canker sores are considered an open sore, they can be quite painful and cause discomfort. Canker sores can appear on the inside of the cheeks, on the inside of the lips, on the tongue, or on the gums. They tend to be white or yellow and are often surrounded by bright red skin.

Canker sores (also called aphthous ulcers or aphthous stomatitis) are the most common oral tissue disease in North America and are usually self-diagnosable and self-treatable. It’s estimated that around half to two-thirds of all U.S. adults will have a canker sore at some point in their life. Canker sores shouldn’t be confused with cold sores, which are sometimes called fever blisters. Cold sores appear on the outside of the mouth and are caused by the herpes simplex virus (HSV).

Sometimes called mouth sores, canker sores happen inside the mouth and cause symptoms of pain, difficulty chewing, and difficulty talking. “Less common symptoms that accompany canker sores include tiredness, weight loss for no apparent reason, swollen lymph nodes, or even an oral thrush infection or fever,” says Carrie Lam, MD, medical director of Lam Clinic. “Consult your healthcare practitioner if your canker sores last for more than three weeks, spread, or if you have a fever or severe pain.”

Even though there’s no cure for canker sores, the pain that comes along with them can be treated with mouthwashes, lozenges, over-the-counter pain medications, and the occasional prescription medication. Minor canker sores will go away on their own within days or weeks, but severe cases may need medical attention.

How is a canker sore diagnosed?

Canker sores might be self-diagnosable for people who’ve had them before, but some people may need to visit a doctor in order to get a proper diagnosis. Typically, mouth ulcers will appear on the gums, tongue, or inside of the lips and cheeks. They’ll be white, yellow, or gray in color, and be surrounded by reddish skin.

Although the exact cause of canker sores is unknown, many researchers believe they’re caused by one or more of the following:

  • Viruses
  • Bacteria
  • Hormonal changes
  • Vitamin deficiencies
  • Stress
  • Weakened immune system
  • Food sensitivities or allergies

Canker sores are very common, and women are more likely to experience them than men. A primary care physician or dentist will be able to diagnose and treat canker sores. If you go to the doctor or dentist for your canker sore, here are some questions you might get asked:

  • Are you experiencing any pain, difficulty chewing, or difficulty talking?
  • Have you recently experienced any stressful life experiences?
  • Do you have a family history of canker sores?
  • Are you taking any medications?

Canker sore treatment options

Once you’ve self-diagnosed your canker sore or been told by a doctor that you have one, the next step is proper treatment. Because there’s no cure for canker sores, treatment options typically focus on pain relief.

Here are some of the most common treatment options for canker sores:

  • Mouthwashes/rinses
  • Topical creams, pastes, or gels
  • Lozenges
  • Over-the-counter (OTC) pain medications
  • Prescribed antibiotics or antivirals

To help keep canker sores from coming back, here are some things you can talk to your doctor about doing:

  • Reducing stress
  • Eating a healthy diet with fresh fruits and vegetables
  • Avoiding rough, spicy, and acidic foods
  • Getting enough nutrients

Canker sore medications

There are several different types of medications that can be used to treat canker sores. The type of medication you’ll need will depend on your individual symptoms and medical history.


Some canker sores are caused by viruses, and if this is the case, antiviral medications may be needed. Some antivirals like Abreva and Denavir are applied topically, and some are taken orally like Valtrex (valacyclovir). Common side effects of antivirals include nausea and headaches.


When canker sores aren’t going away after about a week, or if someone has recurrent canker sores, they may need to take an antibiotic. Antibiotics like Vibramycin (doxycycline)  and Oracea (doxycycline) have to be prescribed by a doctor and may cause side effects like diarrhea, cold-like symptoms, and stomach pain.


Anesthetics are medications that can help relieve pain symptoms that come from having a canker sore, which decreases any difficulty with chewing. They work by numbing the painful area. Two of the most popular anesthetics for cold sores include Cepacol and benzocaine. It’s possible for anesthetics to cause allergic reactions and other side effects like itching or hives.

Anti-inflammatory medications

Canker sores can be painful and even make it difficult to chew properly. Over-the-counter pain medications like Advil (ibuprofen), Aleve (naproxen), and Tylenol (acetaminophen) can help treat pain that comes with canker sores. You shouldn’t take medications like Advil (ibuprofen) or Aleve (naproxen) if you’re allergic to nonsteroidal anti-inflammatory drugs (NSAIDs).


Steroid medications are sometimes used to treat canker sores if they’re becoming worse and not going away. Some doctors will prescribe mouth rinses with steroids in them, or they’ll inject steroid medications like Decadron (dexamethasone). Steroids help reduce swelling and pain, but they can also cause side effects like stomach pain, vomiting, and skin irritation.

What is the best medication for canker sores?

There’s no one universal canker sore medication that will work best for everyone. Individual symptoms and responses to treatment vary. A doctor can determine the best medication for canker sores based on an individual’s symptoms, medical history, and response to treatments. Here’s an overview of popular medications that a doctor or healthcare provider may prescribe or recommend.

Best medication for canker sores
Drug name Drug class Administration route Standard dosage Common side effects
Abreva Antiviral Topical Applied topically as directed on the package or by a medical professional Sensitivity reaction
Cepacol Local anesthetic Oral Lozenges should be taken as directed on the package or by a medical professional Mouth irritation, tongue or teeth discoloration
Decadron (dexamethasone) Glucocorticoid Injection Injected by a medical professional Nausea, vomiting, skin irritation
Denavir Antiviral Topical Applied topically as directed on the package or by a medical professional Headache, redness
Vibramycin (doxycycline) Tetracycline antibiotic Injection Injected by a medical professional Diarrhea,cold-like symptoms, stomach pain
Oracea (doxycycline) Tetracycline antibiotic Oral One 40mg tablet taken once a day in the morning on an empty stomach Diarrhea, cold-like symptoms, stomach pain
Valtrex (valacyclovir) Antiviral Oral 2 grams taken twice daily, 12 hours apart Headache, nausea, stomach pain, cold-like symptoms

Dosage is determined by your doctor based on your medical condition, response to treatment, age, and weight. Other possible side effects exist. This is not a complete list. 

What are common side effects of canker sore medications?

As with any medication, there’s always the potential for side effects. Common side effects of canker sore medications include dry mouth, upset stomach, nausea, vomiting, diarrhea, dizziness, and skin rashes. The table above includes side effects for specific medications.

Although it’s rare, canker sore medications may cause allergic reactions that could be life-threatening. Allergic reactions can cause hives, difficulty breathing, and swelling of the face or throat. You should seek immediate medical advice if you believe you’re experiencing an allergic reaction.

This list of side effects is not comprehensive. The best way to learn more about side effects that could happen from taking canker sore medications is to talk with your doctor or pharmacist.

What are the best home remedies for canker sores?

Many people rely on home remedies and lifestyle changes to help treat their canker sores. Here are some popular home remedies for canker sores:

Gargling with apple cider vinegar

When you have a canker sore, gargling with equal parts apple cider and warm water can help kill bacteria. If you do this every day, you’ll help kill bad bacteria around your canker sore and may speed up the healing process.

Avoiding certain foods

Eating rough, spicy, and acidic foods while you have a canker sore can make it worse. Rough foods like nuts, spicy foods, and acidic foods like orange juice can irritate cold sores and cause them to become more painful.

Get enough nutrients

One of the things that can cause canker sores is a weakened immune system. Making sure you’re getting enough vitamin B12, folic acid, and iron can help canker sores go away. These nutrients have been linked with helping canker sores. Eating lots of fresh fruits and vegetables can also help strengthen your immune system.

Swab with hydrogen peroxide

Applying equal parts hydrogen peroxide and water to your canker sore with a cotton swab once a day may help clear it up. Staying away from food for 15-30 minutes before and after swabbing with hydrogen peroxide helps ensure that it works.

Frequently asked questions about canker sores

How long do canker sores last?

The average canker sore will go away by itself within three weeks, but more serious ones can last for several weeks. The amount of time it takes your canker sore to go away will depend on your general health and what types of medications you’re treating it with.

What causes canker sores? Can stress cause canker sores?

Although the exact cause of canker sores is unknown, there are multiple things that can trigger them. Certain diseases like Celiac Disease, HIV/AIDS, and inflammatory bowel disease (IBD) can all trigger canker sores because they suppress the immune system.

Being stressed out can also cause canker sores because of the way stress negatively affects the immune system. Additional triggers for canker sores include low B vitamin and iron levels, hormonal shifts, and food sensitivities.

Is it good to put salt on canker sores?

Rinsing or gargling with salt water can help canker sores feel less painful and clear them up. Salt should be dissolved in water before it’s applied to a canker sore.

What is the best medication for canker sores?

There isn’t one single medication that’s best for canker sores, but here’s a list of some of the most effective ones:

  • Antivirals
  • Anesthetics
  • Steroids
  • Antibiotics

How do you heal a canker sore fast?

To heal a canker sore fast, you have several options. Gargling with salt water, hydrogen peroxide and water, or apple cider vinegar and water can help kill bacteria that make canker sores worse. Taking zinc lozenges can help boost the immune system, and so can B vitamins and iron.

What can you eat to get rid of canker sores?

Avoiding rough, spicy, and acidic foods can help keep canker sores from getting worse. Eating lots of fresh fruits and vegetables can help build the immune system and help canker sores heal. Soft foods like yogurt and soup can make chewing less painful and keep canker sores from getting aggravated.

How to treat pain from canker sores

One of the worst things about having a canker sore is how painful they can be. To help treat pain that comes with canker sores, try gargling with saltwater, hydrogen peroxide, and water, or apple cider vinegar and water. Medications that can help with pain include lozenges, topical creams, over-the-counter pain medications, and some prescription medications (see the table above).

Related resources for canker sores