The People's Perspective on Medicine

Will Special SLS-Free Toothpaste Prevent Canker Sores?

Many readers have found that switching to toothpaste without SLS helps them stay free of canker sores. Some research supports this link.

Do you pay attention to the kind of toothpaste you use, beyond the flavor? The American Dental Association wants you to use a toothpaste with fluoride because it prevents cavities. Some readers take an extra step, however. They tell us that seeking out toothpaste that does not contain the foaming agent SLS helps them avoid canker sores. This is a simple solution to add to home remedies for these painful lesions.

SLS-Free Toothpaste Makes Mouth More Comfortable:

Q. I had canker sores for years until I discovered Biotène toothpaste. It is formulated especially for people with dry mouth and does not contain sodium lauryl sulfate.

My gums are healthier, and I’ve had no cavities since it contains fluoride. It is more expensive but it’s worth it not to suffer from canker sores.

A. We have heard from many readers that the foaming agent SLS (sodium lauryl sulfate) can be irritating to their mouths and gums. A toothpaste without SLS, like Biotène, may be a good choice for someone like you.

Although scientists conducted an early study on the effect of this foaming agent in 1994, relatively little research been published (Acta Odontologica Scandinavica, Oct. 1994). A recent meta-analysis included four randomized controlled trials (Journal of Oral Pathology & Medicine, May 2019). The authors report that people using SLS-free toothpaste are less likely to suffer recurrent canker sores. 

Looking for Toothpaste That Won’t Aggravate Canker Sores:

Q. I suffered for years with chronic canker sores. I read that SLS (sodium lauryl sulfate) in toothpaste can trigger this painful problem. How do I find toothpaste without SLS?

A. Some readers report that Biotène toothpaste is SLS-free and helps reduce canker sores (known as aphthous ulcers in medical lingo). Certain toothpaste options from Tom’s of Maine, Rembrandt and Sensodyne Pronamel are also devoid of SLS. Read the labels carefully to make sure the one you purchase does not contain sodium lauryl sulfate.

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Judith had this to say:

“It is very true that toothpaste can cause canker sores and in my case fever blisters also. I am now using WELEDA Salt Toothpaste and am free of the canker sores. Tom’s of Maine is also good. No SLS in either of these.”

LGF made this suggestion:

“I am a dental hygienist. For years, I have cautioned patients to be aware of mouth irritations, cracks in the corners of their lips, or sensitive teeth when they changed toothpaste brands. A lot of tartar-control and whitening toothpastes can cause irritations and sensitive teeth. A patient who often has mouth ulcers told me once that they were almost entirely eliminated by rinsing with Listerine everyday. That made a lot of sense to me, and I pass that info along to all my patients with mouth ulcers.”

TC agrees with the Listerine recommendation:

“I get canker sores on my tongue whenever I eat spicy foods (chile, jalapenos), cinnamon candy disks, fresh or canned pineapple or Starburst candy  and when I’m stressed. What works almost immediately is Listerine. I rinse three times a day and before bedtime.

“There is one other mouthwash that helps too. It’s Dr. Tichenor’s Peppermint mouthwash concentrate. Do not use full strength nor swallow. Dilute with 5 parts warm water and use as needed. It is a little pricey but well worth the positive results. By morning, my canker sores are almost gone but I continue rinsing for several days.

“I use this same mouthwash (Dr. Tichenor’s) for sore throat and by morning my throat feels a lot better. These are my personal preferences. If you try them, I hope they give you some well deserved relief.”

Another reader chimed in on toothpaste with SLS:

“I am so grateful that finally after years and years of suffering with canker sores, I found that a simple change to a non SLS toothpaste immediately halted any further sores within 5 days. Sensodyne Pronamel has made a world of difference to me. I have also started taking lysine capsules and using a recommended non alcohol based mouthwash.

“The thing I’m mad at most are the toothpaste companies who put in this ingredient. It is only there to create a foaming action, with no benefits at all. However, it also causes a small percentage of people to suffer with mouth ulcers with no idea as to why they are getting them. If you have constant canker sores, I can highly recommend this simple change of using a non SLS toothpaste.”

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About the Author
Terry Graedon, PhD, is a medical anthropologist and co-host of The People’s Pharmacy radio show, co-author of The People’s Pharmacy syndicated newspaper columns and numerous books, and co-founder of The People’s Pharmacy website. Terry taught in the Duke University School of Nursing and was an adjunct assistant professor in the Department of Anthropology. She is a Fellow of the Society of Applied Anthropology. Terry is one of the country's leading authorities on the science behind folk remedies. .
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  • Herlofson BB & Barkvoll P, "Sodium lauryl sulfate and recurrent aphthous ulcers. A preliminary study." Acta Odontologica Scandinavica, Oct. 1994.
  • Alli BY et al, "Effect of sodium lauryl sulfate on recurrent aphthous stomatitis: A systematic review." Journal of Oral Pathology & Medicine, May 2019. DOI: 10.1111/jop.12845
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Yes, I believe that SLS causes canker sores. I read about SLS a few years ago and switched to toothpaste without it and I have not had an issue.

After switching to Trader Joe’s anti-cavity peppermint toothpaste without SLS, I went from frequent and painful canker sores to only occasional mild sores.

I was plagued by ulcers in the corners of my lips–perleche–for a long time. I switched to a natural toothpaste called David’s, which has no SLS, two or three years ago and have been ulcer-free. I buy it on Amazon.

I have been using Trader Joes fennel propolis and myrrh toothpaste for years. It has no fluoride or SLS. I also put a drop of oil of oregano on the brush to eliminate bacteria in my mouth. I personally get a lot of canker sores in my mouth still but a drop of oil of oregano on them a few times gets rid of them before they get going.

Yep, all my life I had canker sores and blisters in my mouth. When I changed toothpaste they disappeared and I’ve not had them since. This has been 7+ years. I currently use sensodyne pronamel because I have sensitive teeth/gums. Great that it’s reasonably affordable.

My hygienist says the sis helps the toothpaste stick to your teeth and do a better job.

Jason toothpaste: TRULY a natural toothpaste unlike others that claim to be. It is SLS free. I discovered two decades ago that SLS was the cause of my chronic canker sores. Use the Jason.

I now choose toothpastes without fluoride and without sodium laurel sulfate (nothing with that type of name either, including ‘sodium laureth sulfate’).

I used to suffer from canker sores, and I don’t much anymore. I also cut out most sugary foods and I really attribute my mouth ulcers to sugary or acidic foods, but harsh chemicals could surely have a contributing factor.

I say get rid of the garbage. Out with the junk! In with the gooood stuff.

Peroxide and baking soda, or just peroxide, works very well and has a foaming action if you like that sort of thing.

Several years ago I switched from Colgate to Pepsodent toothpaste. After a few months I began to get little red bumps on my lip line. As soon as one healed another appeared. After much sleuthing I determined it must be SLS. I changed to Earthpaste by Redmond ( it’s clay and salt) and the red bumps stopped. If I use a toothpaste with SLS the bumps return. After years of sensitive gums I have no pain when I visit the dentist and my gums feel healthy.

Tom’s of Maine, while it is my preferred toothpaste, does indeed contain SLS.

I switched to Jason’s toothpastes after a lifetime of suffering from canker sores (apthous ulcers). My dentist told me it was the SLS that caused these painful ulcers on the sides of my tongue. He also suggested I avoid whitening formulas as those can also trigger canker sores. I haven’t had a recurrance since I made the switch. However I prefer whitening formulas so I tried Jason’s Powersmile… My teeth gleam and I’ve been canker sore free for over 10 years!

Yes! This works! My husband and I both suffered from a lot of canker sores and once we removed SLS from our toothpaste, we rarely, if ever have canker sores anymore. Another thing I do is rinse with mouthwash and take Vit. B Complex if I have any mouth irritation and/or minor cuts from brushing. The combination of the three things together has saved me from a lot of mouth pain over the years and I’m so very thankful for it!

SLS free toothpastes make a big difference for me.Wish Tom’s of Maine still had a variety without SLS but with fluoride as I like their products but other options.

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