Ever get a painful sore after brushing? Stress or spicy food might not be the cause—Sodium Lauryl Sulphate (SLS) in many toothpastes can trigger canker sores. Learn what SLS is, why it’s used, and how switching to an SLS-free toothpaste can keep your mouth comfortable and sore-free.
Introduction: A Common Irritant Hiding in Plain Sight
Have you ever brushed your teeth, only to find a painful little sore inside your mouth a day or two later? You might chalk it up to stress, biting your cheek, or spicy food. But what if your toothpaste was partly to blame? Many people are surprised to learn that an ingredient called Sodium Lauryl Sulphate (SLS), found in most conventional toothpastes, may be the culprit behind those annoying canker sores.
This blog breaks down what SLS is, why it's used, and how switching to an SLS-free toothpaste could save you a lot of discomfort. We’ll keep things simple and easy to understand—no science degree needed.
WHAT IS SLS, AND WHY IS IT IN TOOTHPASTE?
Sodium Lauryl Sulphate (SLS) is one of the most common ingredients used in many cleaning and personal care products. You’ll find SLS in things like floor cleaners, car wash soaps, shampoos, shower gels—and yes, even in your toothpaste. It's mainly added for its ability to create foam and help remove grease and grime.
Sodium Lauryl Sulphate (SLS) is a foaming agent. It helps create that nice, bubbly lather when you brush your teeth, which makes the toothpaste feel like it's doing a thorough cleaning job. But here’s the thing: it doesn't actually clean your teeth better. It just gives you that "clean feeling."
SLS is also used in shampoos, soaps, and even household cleaners. It helps lift away dirt and oil, but in the mouth, it can be a little too harsh.
HOW SLS MIGHT BE CAUSING TROUBLE
Here’s the problem: using SLS regularly, especially in products that go in your mouth, can sometimes lead to unwanted side effects. Some people may develop allergic reactions or other sensitivities from it.
And when it comes to your mouth, SLS can be even more irritating. Since toothpaste comes in direct contact with the soft tissues inside your mouth, SLS can sometimes get absorbed through the cheeks or under the tongue, potentially leading to oral issues like canker sores or other forms of irritation. 1
Canker sores are small, round ulcers that form inside your mouth. They’re not contagious, but they can be super painful, especially when eating or drinking. While canker sores can have many triggers (stress, hormones, certain foods), SLS is believed to irritate the soft tissues inside the mouth. It can strip away the natural protective layer of mucus, leaving your gums and cheeks more vulnerable. For some people, this irritation leads directly to frequent and painful canker sores. If you've tried everything to get rid of them, but they keep coming back, your toothpaste might be worth a second look.
SIGNS SLS MIGHT BE AFFECTING YOU
Not everyone reacts to SLS in the same way. But here are a few signs it could be bothering you
- You get canker sores regularly, especially after brushing.
- Your mouth feels dry or sensitive after using toothpaste.
- You have a burning sensation on your tongue or inside your cheeks.
Of course, these could have other causes too. But if you’ve never tried an SLS-free toothpaste, it might be worth seeing if it makes a difference.
BENEFITS OF GOING SLS-FREE
Switching to an SLS-free toothpaste may sound like a small change, but for many people, it makes a big difference. Here are a few benefits:
- Gentler on Sensitive Mouths: If your mouth tends to feel raw or irritated, SLS-free products are often milder and more soothing.
- Better for People with Allergies: People with oral allergies often do better with gentler products.
- Still Gets the Job Done: SLS-free doesn’t mean ineffective. These toothpastes still clean your teeth well—just without the bubbles.
HOW TO CHOOSE THE RIGHT SLS-FREE TOOTHPASTE
If you're ready to try an SLS-free option, here are a few things to look for:
- SLS-Free should be clearly labelled.
- Look for soothing ingredients like Lactoferrin.
- Bonus if it contains Nano-Hydroxyapatite, a modern alternative to fluoride for enamel repair.
DENTE91: A THOUGHTFULLY CRAFTED ALTERNATIVE
At Dente91, we believe oral care should be effective, gentle, and science-backed. That’s why all of our toothpastes are 100% SLS-free, helping reduce irritation while still delivering powerful cleaning and enamel repair.
Our range is formulated with modern ingredients like Nano-Hydroxyapatite and Lactoferrin that help support healthy enamel, reduce inflammation, and fight bad bacteria – all without the harshness of SLS.
If you're tired of the sting and the sores, it might be time to make the switch to something better.
SMALL INGREDIENT, BIG IMPACT
Sometimes the ingredients we overlook are the ones making the biggest impact on our health. If you’ve been struggling with mouth sores, discomfort, or irritation, your toothpaste could be playing a bigger role than you think.
By removing SLS from your routine, you’re giving your mouth a chance to heal and thrive—without compromising on cleanliness or freshness. It’s a simple swap that could bring major relief.
Give your mouth the care it deserves. Try an SLS-free toothpaste and feel the difference.
1. https://pmc.ncbi.nlm.nih.gov/articles/PMC5573534/