Do Certain Toothpastes Cause Canker Sores?

Many toothpastes contain an ingredient called Sodium Lauryl Sulfate (SLS). SLS is a strong detergent and has demonstrated in several studies to increase canker sore outbreaks and pain.

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Do Certain Toothpastes Cause Canker Sores?

Dr. Burhenne, I’ve heard that certain toothpastes can cause canker sores. Is this true?

A: Many toothpastes contain an ingredient called Sodium Lauryl Sulfate (SLS). SLS is a strong detergent and has demonstrated in several studies to increase canker sore outbreaks and pain.

SLS is a surfactant and a foaming agent found in most household soaps and detergents. It gives you that bubbly, foamy feeling when you’re brushing that manufacturers know make you feel like your mouth is cleaner.

That foamy feeling from SLS might feel good, but SLS actually strips away the protective lining of the mouth.

SLS is rated as high hazard for irritation and a moderate hazard for organ toxicity by EWG’s Cosmetic Database. It’s strong stuff — the cleaning solution I use on our garage floor is 50% SLS.

I can tell when my patients are using a toothpaste with SLS in it because of the sloughing of cheek cells on my intraoral mirror. It’s one of the most recognizable conditions in the mouth.

But there’s no reason to accept a hazardous chemical in your toothpaste.

All toothpaste needs to be to do the job is to be a mild polishing or abrasive agent that assists the toothbrush in removing biofilm. Anything beyond this is not part of the efficacy of the toothpaste — rather, a marketing battle for shelf space.

The mouth is a sensitive area that you never want to strip clean or dry out. Several studies showed that SLS breaks down the protective lining of the mouth, leaving the underlying tissues irritated and prone to break out in canker sores.

I recommend to all my patients and readers — whether they’re prone to canker sores or not — to use an SLS-free toothpaste.

SLS-free toothpastes have caught on and are now becoming mainstream. You’ll find them at Whole Foods, Amazon, and even Safeway or Walgreens — [Pinterest board.]

Beware that manufacturers are also hiding SLS in their ingredients under different names, as SLS-free toothpaste becomes more popular (from the EWG Cosmetics Database):

  • Monododecyl ester sodium salt sulfuric acid
  • Sodium Dodecyl sulfate
  • Sodium dodecyl sulphate
  • Sodium salt sulfuric acid
  • Monododecyl ester
  • Sulfuric acid monododecyl ester sodium salt
  • Sulfuric acid
  • Monododecyl ester
  • Sodium salt
  • A13-00356
  • Akyposal SDS
  • Aquarex Methyl

I recommend that all my patients switch to an SLS-free toothpaste, especially those suffering from frequent canker sores.

What to do:

  • If you suffer from canker sores, allergic reactions in the mouth, or other types of irritation, try switching to an SLS-free toothpaste for 30 days and track your results to see if there’s an improvement.
  • Check if your toothpaste has SLS, check this database:
  • Check out my Pinterest board of my favorite SLS-free toothpastes, all taste-tested and approved by me

Don’t become a part of this battle for shelf space when making decisions for a product that can impact your good health. Whether you’re prone to canker sores or not, SLS is an unnecessary hazardous chemical and SLS-free options abound.

Dr. Mark Burhenne DDS

Read Next: Cold Sores vs. Canker Sores: Why You Should Know the Difference

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Leave a Comment

  1. Meryl Jefferson says:

    Thank you for this article. I have been suffering for about 4 months with sloughing mouth cells and canker sores in my mouth. I have been unable to figure it out until I read this article. I just brushed with Pronamel Sensitive and rinsed with Biotene. Tomorrow I am going shopping for new toothpaste. (The Pronamel was a sample I had in my drawer.) I have been using Crest Pro Health for years and years.

  2. This was absolutely 100% true for me. I used to suffer from canker sores about once a month. About ten years ago I did some research and found out about SLS. Since switching (my favorite SLS-free toothpaste is no longer made), I’ve had maybe 2-3 canker sores in that ten years. Once in a while I would feel the tingle of an impending canker sore, but they wouldn’t materialize. If I ever hear anyone talking about canker/inner mouth sores I share this information.

    • Kendra Nelsen says:

      HI I have sore mouth tissues ALL the time and can’t eat many foods b/c of it. Can you tell me ANY brands of toothpaste to try? PLEASE HELP. Thanks Kendra

      • Hi Kendra, I use Earth Paste by Redmond. I really like it.

    • Fully agree! I also switched about 10 yrs ago and now no longer get mouth ulcers.

  3. Cankers are the absolute worst. I’ve found great luck with the canker spanker.

  4. Thank you for this article! I was at a loss as to why my gums are suddenly red and sore, and I have developed canker sores for the first time in my 50 some years of life. I had recently begun using two new toothpastes, Colgate Enamel Health and Colgate Clean-In-Between toothpaste, both of which list the sodium lauryl sulfate as an ingredient. I was under the mistaken impression that they would help with my oral care, not hurt it.

  5. Kendra Nelsen says:

    PLEASE HELP…can anyone tell me brands of toothpaste to try? My mouth tissues are sore all the time and I can’t eat many good foods b/c of it. I’ll be grateful for any specific ideas!

  6. Dana Phillips says:

    Today, there are many companies which make natural toothpastes free from Sodium Lauryl Sulfate. Some of the most popular are:

    Jason Natural Cosmetics Toothpaste
    Squigle Enamel Saver Toothpaste
    Sensodyne ProNamel Mint Essense Toothpaste
    Auromere SLS Free Herbal Toothpaste
    Kiss My Face Kids Berry Smart Toothpaste
    Xyliwhite platinum mint

  7. For years I was plagued with what I thought were never ending recurring cold sores which would manifest usually near the corners of my mouth – but on the outside, not inside the mouth like a canker sore. They would appear, eventually scab over and heal, and then another would take its place. The symptoms fit oral herpes exactly and that’s just what my general practitioner thought they were. I was prescribed antiviral medications including Valtrex and two others to use as a suppressive therapy, but even though I took them religiously they didn’t seem to make any difference.

    After many months of this never ending hell, my doctor finally had me take a blood test for herpes simplex 1 and 2, and the results came up completely negative! That’s great but I still needed to find out WTF was going on with these mouth sores so he referred me to a dermatologist who said they were possibly being triggered by my toothpaste and that I should try a brand that is both fluoride and SLS free. I was skeptical to say the least, but I picked up a tube of ‘Tom’s of Maine’ no fluoride toothpaste and bingo, that was the end of the “cold sores”. It’s been close to a year and they haven’t come back, I just wished I had known sooner so I wouldn’t have literally lost years of my life.

    • Moises Arias says:

      Doesnt that toothpaste have sls?

  8. Pauline Eboigbe says:

    Thanks Dr. I appreciate this article. It came at the right time.

  9. stephen hobbs says:

    allergym to saccarin is also a high probability, it’s a common ingredient in almost all mainstream toothpastes, I know because I AM allergic to saccarin.

    • Mark Burhenne, DDS says:

      Great point, Stephen! I do NOT recommend artificial ingredients.

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