How to Get Rid of Canker Sores

Canker sores, which are sometimes called mouth ulcers, can form anywhere inside of the mouth (on the gums, inner cheeks and lips). They are irritated looking blisters and can be very painful. It can happen multiple times in a single month, which is not pleasurable. While annoying, it is pretty simple to get rid of canker sores on your own, using a number of home remedies. Read on to learn how to get rid of canker sores.

how to get rid of canker sores

What Causes Canker Sores

The exact cause of most canker sores is unknown, though researchers suspect that a combination of several factors contributes to outbreaks. The most common causes include:

  • Allergies of food sensitivities.
  • Allergy to certain bacteria in the mouth.
  • Injury to the mouth.
  • Smoking.
  • Acidic foods, including citrus fruits.
  • Toothpaste containing sodium lauryl sulfate.
  • Diets low in vitamins B12, zinc, folate (folic acid), or iron.
  • Emotional stress.
  • Hormonal shifts during menstrual cycle.
  • Autoimmune disorders such as Behcet’s disease or systemic lupus erythematosus.
  • Gastrointestinal tract diseases such as Crohn’s disease or Celiac disease.

Home Remedies for Canker Sores

Use a 3% hydrogen peroxide solution. Hydrogen peroxide is an antiseptic that will reduce the amount of bacteria in your mouth and help the canker sore heal.

  • Pour a little bit of it into a plastic soda cap and dilute with an equal amount of water.
  • Dip the Q-tip into the peroxide solution and dab it only on the canker sore.
  • Turn the Q-tip around and repeat.
  • Empty the cap and rinse it with water.
  • Take care not to swallow any of the hydrogen peroxide if possible.
  • The canker sore should go away in about 2-3 days if you do it twice a day.

Use a saline rinse. Rinsing your mouth with a saltwater solution can help disinfect your mouth ulcer, keeping it clean from the bacteria that naturally occurs in your mouth and preventing aggravation.

  • Mix a teaspoon or two of salt with a warm glass of water. The exact ratio isn’t important, as long as you’re not using so much salt that you can’t keep the water in your mouth. If you don’t have salt handy, or you can’t handle the taste, use a pinch of baking soda instead.
  • Hold the saline solution in your mouth, and swish from side to side.
  • Spit the solution into the sink. Don’t swallow it — otherwise, you’ll find yourself dehydrated.
  • Repeat a few times a day. It’s a good idea to do it again after meals and before you go to bed.
  • Apply some honey on the ulcer. It may hurt a bit when you apply it. But it it is quite effective.

Suck on ice chips. The cold can reduce the swelling of the sore, as well as numbing the pain. If you can, use your tongue to hold a chip directly against the sore.

  • Carry around a cup of chips, if you can. Keep them in a coffee thermos or a styrofoam cup to prevent rapid melting, and use them throughout the day.
  • Drink cold water. If ice chips are too cold for you, try to at least drink cool water throughout the day.

Use coconut oil. Antimicrobial and anti-inflammatory, coconut oil is almost fail-safe when it comes to getting rid of canker sores.

  • Using cotton swab or clean hands, apply a liberal amount of coconut oil onto the sore.

Use a lemon. Squeeze the lemon with a lemon squeezer or just squeeze is on the ulcer straight away.

  • If you squeezed the lemon with a lemon squeezer, wash your hands, put your finger in the juice then dab it on your ulcer.
  • Repeat it before breakfast, after breakfast, before lunch, after lunch, before tea, after tea, before dinner, after dinner and right before you sleep.
  • Leave it on for 1-5 minutes. Then rinse off, if needed.

Use baking powder and lemon.

  • Mix 1/4 of a teaspoon of baking powder with a freshly cut lemon; squeeze all the juice out, into the baking soda.
  • Add a tablespoon of cold water and half a teaspoon of honey.
  • Finally, mix until it’s all blended in.
  • Apply it to your ulcer. Do this twice every day, once in the morning and once when you’re going to sleep. After a week, this should have cleared the ulcer.

Eat yogurt. Plain yogurt with live cultures not only helps restore a healthy balance to gut flora, but also is one of the best home remedies to get rid of canker sores.

  • Make sure the label confirms that it contains live cultures.
  • Eat 1 tablespoon 3 times daily (minimum).
  • Try adding a little bit of raw honey for taste.

Use mouthwash. Rinsing out your mouth more often will clear out any aggravating bacteria, as well as easing the pain of the sore in some cases.

  • Use an over-the-counter solution. Just about any mouthwash will work for this purpose. Swish it morning and night, and maybe after lunch as well.
  • Use a diphenhydramine suspension wash. These rinses, such as Benadryl Allergy liquid rinse, can help dull the pain as well.
  • Spit it out. Never swallow mouthwash.

Use an antihistamine/antacid mix. Combine one part diphenhydramine (sold as Benadryl) with 1 part antacid, such as Maalox or Kaopectate. Swish around your mouth and spit out.

Use milk of magnesia. Dab it on active spots a few times a day. The antacid effect of milk of magnesia neutralizes the acidic environment, changing the pH, and making it less supportive of the bacteria in the mouth that aggravate the canker sore.

Manage pain. If you can’t get rid of your mouth ulcer as soon as you’d like, you can at least try to forget about it.

  • Take an over-the-counter pain reliever. Avoid taking aspirin if you’re 18 or younger.
  • Use a numbing gel. These are sold over-the-counter at most drug stores for infant teething or toothaches. Dab it gently on the sore every few hours.

How to Treat Canker Sores with Prescription Medications

Request topical gels and ointments. Topical ointments such as benzocaine (Anbesol), amlexanox (Aphthasol) and fluocinonide (Lidex, Vanos) may relieve pain and speed healing if applied as soon as canker sores appear. Doctors usually suggest treating sores with ointments 2-4 times during the day.

Request cauterization. Cauterizing — or burning the surface tissue — sores can keep open sores from getting bigger, and the burn will eventually heal over. Most cauterizations are performed with chemical solutions, such as silver nitrate.

Request a prescription mouth rinse. You have two options for prescription mouth rinses:

  • Tetracycline, an antibiotic used for more extreme cases. Your sores will heal quickly, but your mouth will be susceptible to a fungal condition called thrush. Thrush is an infection of yeast fungus in the mucous membranes of the mouth.
  • Dexamethasone, a steroid mouth rinse that should reduce pain and inflammation. Dexamethasone should reduce the number of recurrences, but is generally reserved for more severe cases.

Professional Treatment for Canker Sores

Visit a specialist if you get frequent sores. If you’re constantly battling canker sores and none of the above fixes are working, perhaps there’s an underlying issue. For some conditions, canker sores are an early and important sign that something else is wrong.

Visit a dentist if the sore lasts for three weeks or more. Most mouth ulcers should go away on their own in two to three weeks. If yours is still sticking around, schedule an appointment with a dentist.

  • A dentist can help you make sure your problem is actually a mouth ulcer, and not a tooth abscess or a rare form of oral cancer.

Schedule an appointment with an immunologist. Consider visiting an immunologist. There are a few rare immune conditions that can manifest as persistent mouth sores.

Schedule an appointment with a gastroenterologist. Consider investigating whether you have Celiac Disease, Crohn’s Disease, or inflammatory bowel disease. All three are autoimmune conditions that can cause frequent mouth sores.

  • You might also ask the doctor if it’s possible you have Helicobacter pylori, more commonly known as H. pylori, which can cause stomach ulcers.

How to Prevent Canker Sores

Try to stop the cause. Canker sores can be caused by a variety of factors. If you have several cankers or you get them repeatedly, consider:

  • Brushing your teeth more gently. Brush your teeth gently with a soft-bristled toothbrush. Floss daily.
  • Changing your toothpaste. Toothpastes or mouthwashes that contain sodium lauryl sulfate can cause canker sores and continue to aggravate them. Try substituting natural toothpaste into your regimen.
  • Relaxing. Many people get canker sores during times of intense emotional stress. Like acne and eczema, canker sores can be exacerbated by stressors.

Protect your mouth from damage caused by trauma.

  • Use a soft bristled toothbrush.
  • Chew your food slowly.
  • Allow foods and drinks to cool to a comfortable level before you consume them.
  • Avoid tobacco, chewing gum and lozenges.
  • See your dentist if you have a sharp or broken tooth or denture.
  • Choose toothpastes and mouthwashes that do not contain sodium lauryl sulfate.

Pay attention to your diet. Diet can have a significant effect — beneficial and detrimental — on canker sores.

  • Avoid spicy or acidic foods, which can irritate sores further. Peppers and sodas should be shunned. Fruits and vegetables such as lemons, oranges, pineapples, apples, figs, tomatoes, and strawberries may also cause canker sores.
  • Get more B12, zinc, iron, and folic acid. Take a vitamin supplement, or multiple supplements, that contain these every morning.
  • Eat more yogurt and other foods that contain live and active cultures to promote a healthy bacteria level in your mouth and body.

Look for connections between your diet and outbreaks of canker sores. In addition to food allergies, some people have found that acidic foods, like citrus fruit, tomatoes and vinegar, can trigger the sores.

Increase the amount of lysine in your diet. Good sources of lysine include fish, chicken, eggs, and potatoes.

Take a lysine nutritional supplement. Nutritional lysine supplements, like L-lysine, provide essential amino acids that help with tissue growth and repair. This can reduce the occurrence of canker sores and limit the expansion of small canker sores.

Treat other medical conditions that may cause or make canker sores worse.Simple canker sores, which are common and appear three or four times a year and last up to a week, are likely not caused by underlying health problems. Complex canker sores, which last longer and are likely to recur, may be due to underlying health problems.

  • Individuals with gastrointestinal tract diseases, such as Celiac disease and Crohn’s disease, may also be at higher risk for complex canker sores.
  • Individuals with compromised immune systems may be at higher risk for canker sores.

Schedule regular dental check-ups and cleanings. Consistent oral hygiene can prevent mouth ulcers from returning. In addition to brushing your teeth twice a day and flossing once a day, consider seeing a dentist every six months for a professional evaluation and cleaning.


  • Avoid using hydrogen peroxide more than twice weekly or on an ongoing basis as repeated use can prolong the ulcers due to the oxidizing nature of this chemical.
  • If using any method involving salt or baking soda, do not swallow the mixture! It can cause you to throw up. This will bring stomach acid to to your mouth which will irritate the canker sore further.
  • Sometimes canker sores have the appearance of a blister. While it may seem like a good idea to “pop” it or open it up in some way, this is not recommended. Doing this will simply prolong the healing process.


  • Don’t play around with your canker sores using your tongue as this will cause the healing process to take longer.
  • Boil your toothbrush in water.
  • As with most illnesses, drinking lots of water will help your body to heal itself.
  • Unlike cold sores, canker sores or mouth ulcers are not contagious, kissing someone with a canker sore will not harm your partner but may still be uncomfortable for you.