SLS-Free Toothpaste: Why It's Worth Trying If You Get Canker Sores
If you get canker sores that keep coming back, there's one cheap, five-second change worth trying before anything fancy — and it's hiding in the foam.
What is SLS, and why is it in toothpaste?
SLS (sodium lauryl sulfate) is a detergent added to make toothpaste foam. It doesn't clean your teeth — it just creates the lather people associate with "clean."
| The myth | The reality |
|---|---|
| Foam = clean | Foam is just a detergent (SLS). It's a sensation, not cleaning. |
| No foam = not working | Cleaning comes from brushing + a mild abrasive. Foam is optional. |
What's the connection to canker sores?
Several studies have looked at SLS and recurrent canker sores, and some found people had fewer or less painful ulcers after switching to an SLS-free toothpaste.
The research isn't unanimous, and canker sores have many triggers (stress, certain foods, minor injuries). But because SLS is a detergent that can irritate some mouths, going SLS-free is a low-risk thing to test for a few weeks and see if it helps you.
It's one of the most common tips passed around by people who deal with frequent mouth ulcers: "switch to an SLS-free toothpaste and see if it calms down."
What does "SLS-free" actually mean?
It means no sodium lauryl sulfate (and ideally no SLES). Your toothpaste will foam less — that's expected, and doesn't mean it's working less.
The adjustment is mostly mental. Once you stop equating foam with clean, an SLS-free toothpaste feels completely normal.
What to look for
- No SLS / SLES on the ingredient list.
- A short, recognizable ingredient list overall.
- A real cleaning agent (a mild mineral or clay) doing the actual work.
If canker sores are a regular problem, mention it to your dentist too — but trying an SLS-free toothpaste is a simple first step you can take yourself. (Our toothpaste is SLS-free, with no added foaming agents.)