If you switched from Crest to a “natural” toothpaste, I need you to go grab the tube right now.
I’d like you to flip it over and read the ingredients.
If you see peppermint oil, tea tree oil, spearmint oil, wintergreen, clove oil, or cinnamon oil — your “natural” toothpaste is disrupting your oral microbiome.
I know this is hard to hear. You made the switch because you care about what goes into your body. You did the research. You thought you were doing the right thing.
But here’s what nobody told you: essential oils are antimicrobial. That’s the whole point of them — that’s why they’ve been used for hundreds of years in wound disinfection and cleaning products. They are extremely effective at killing microbes. The problem is, they don’t know the difference between the bacteria that are protecting you and the bacteria that are harming you.
Some essential oils are as powerful as chlorhexidine — the nuclear option your dentist prescribes after surgery. And you’re brushing with them. Twice a day. Every day.
So What?
Here’s where the common phrase “they kill bad bacteria but spare good bacteria” breaks down. It’s not just incorrect — it reflects a flawed way of thinking about the oral microbiome.
Your mouth contains over 700 species of bacteria. But they aren’t divided into fixed teams of “good guys” and “bad guys.” Most oral microbes are context-dependent — the same species can be beneficial or harmful depending on the balance of the community around it.
A bacterium that’s perfectly harmless when your ecosystem is stable can become disease-associated when that balance is disrupted.
Health isn’t about killing the right bacteria. It’s about maintaining a stable, functional ecosystem.
Essential oils are inherently bactericidal. They work through non-specific mechanisms — disrupting cell membranes, interfering with metabolic processes — meaning they apply pressure broadly, not selectively.
When you introduce that kind of indiscriminate pressure twice a day, you don’t just remove harmful activity. You destabilize the entire ecology. You reduce beneficial functions. You alter microbial communication.
And the organisms that bounce back fastest in a destabilized environment are the opportunistic ones. The disease-associated ones.
Essential oils don’t just remove harmful activity — they can destabilize the very ecology that keeps your mouth healthy.
This is why some of you are doing “everything right” — brushing, flossing, eating well — and still getting cavities, still getting bleeding gums. Still getting told you need another procedure.
It’s not your fault. It might just be your toothpaste.
It’s Not Just Essential Oils
Once I started looking at toothpaste formulations — really looking — I found problem after problem. Even in the “good” brands. Even in the ones I was recommending to my own patients.
SLS (Sodium Lauryl Sulfate) — the ingredient that makes your toothpaste foam. That foam feels like it’s cleaning your teeth. It’s not. It’s stripping the protective mucosal lining inside your mouth. I could always tell when my patients were using a toothpaste with SLS because of the sloughing of cheek cells I’d see on my intraoral mirror — it’s one of the most recognizable conditions in the mouth. Multiple studies have linked SLS to increased canker sore frequency. The cleaning solution I use on our garage floor is 50% SLS. And this is the ingredient most people are putting in their mouth twice a day.
Emulsifiers — they keep the ingredients blended together on the shelf. Convenient for manufacturing. But emulsifiers can disrupt the delicate balance of your oral microbiome too.
Endocrine disruptors — ingredients like triclosan and certain preservatives that interfere with your hormonal system. In your mouth.
Go read the back of your toothpaste tube — even the one from the health food store — and ask yourself: Do I know what every one of these ingredients is doing inside my mouth?
My Confession
I’ve been writing about this problem for almost a decade. In 2017, I published an article on my website called “Essential Oils — The Potentially Unhealthy Ingredient in Your ‘Healthy’ Toothpaste.” I laid out the science. I cited the studies.
And then at the bottom of that article, I had to make an admission: I was still using Boka — a toothpaste with essential oils in it. Because Boka also contained nano-hydroxyapatite, and at the time, it was the best nano-hydroxyapatite toothpaste on the market. I recommended it to my patients for years. The nano-hydroxyapatite was too important to give up — it was non-negotiable for me.
But the essential oils? The SLS? Those were the tradeoff I accepted, because nobody had made a nano-hydroxyapatite toothpaste without them yet. I even wrote at the end of that 2017 article: “I fully realize that there are hardly any essential oil-free options out there on the market.”
That tradeoff is exactly why I built Fygg.
Fygg is the toothpaste I spent my entire career wishing existed. No fluoride. No essential oils. No SLS. No emulsifiers. No detergents. No endocrine disruptors.
Just ingredients that remineralize your teeth and nourish your oral microbiome instead of destroying it.
No burn. No foam. The first time you use it, it’ll feel different. That’s because you’ve been trained to think toothpaste should sting. That sting was never cleaning your teeth — it was the essential oils and SLS attacking your soft tissue. Once that’s gone, you realize: this is how toothpaste should feel.
And the science backs it up. A 2025 study published in the Journal of Dentistry — conducted at the University of Texas Health San Antonio — tested eight toothpastes head-to-head on their ability to remineralize early enamel caries lesions.
Fygg achieved roughly double the remineralization of Boka, and the difference was statistically significant (p < .01). Fygg also performed on par with prescription-strength fluoride toothpaste (5,000 ppm). You can read the full study here: PubMed
My whole family uses Fygg — my daughters, my grandchildren. It’s the first toothpaste I’ve ever been able to recommend without an asterisk. No ‘it’s great, but…’ No tradeoffs.
>> Try Fygg (code ATD15 for 15% off)
Have a wonderful week,
Mark
Go Deeper
Essential Oils — The Potentially Unhealthy Ingredient in Your “Healthy” Toothpaste — My original 2017 article laying out the science on essential oils and the oral microbiome.
Why Do I Keep Getting Canker Sores? — The full breakdown on SLS, zinc deficiency, and the root causes most dentists miss.
It’s Time for Dentists to Confront the Truth About Fluoride — Why I stopped recommending fluoride, and what the federal court ruling means for your family.
Mark’s Must-Haves for Fluoride-Free (and Cavity-Free) Kids — My full oral care protocol for children — no fluoride required.
Podcast Episode #110: Redefining Tooth Care with Fluoride-Free Innovations
Podcast Episode #107: Fluoride Varnish + New Alternatives
The remineralization study (Journal of Dentistry, 2025) — The head-to-head comparison of eight nano-hydroxyapatite and fluoride toothpastes, including Fygg, Boka, Dr. Jen’s, Risewell, and prescription strength fluoride toothpaste.