Today’s newsletter is a bit more technical. If you enjoy data, this deep dive will interest you—because it dismantles one of the biggest myths in oral health right now.
If you’d prefer the short version, here’s what this article shows:
- The “10% nano-hydroxyapatite” claim is misleading.
- A new peer-reviewed study compared Fygg’s 3.1% nano-hydroxyapatite formula to Boka, Risewell, Just Ingredients, Dr. Jen, Crest Cavity Protection, and ClinPro 5000 (a prescription-strength 5000 ppm fluoride paste).
- Particle quality and design—not just concentration—determine effectiveness.
- Excessive nano-hydroxyapatite can aggregate, reducing enamel binding and diminishing remineralization.
There’s a familiar pattern in health marketing: a misread or outdated study becomes a catchy slogan, and soon everyone treats it like settled truth. We’ve seen similar turns before, where misinterpreted science steers public guidance and consumer behavior in unhelpful directions.
In hydroxyapatite toothpastes, that marketing myth became: “It must be 10% nano-hydroxyapatite—or it won’t work.” That statement doesn’t hold up to current evidence.
Influencers repeated the 10% claim, and some brands built identities around that number—implying that lower percentages are ineffective. I even questioned Fygg’s formulation briefly and asked colleagues and critics for the studies that supposedly proved the 10% threshold. Time and again the evidence didn’t support that conclusion.
After consulting biochemists and oral microbiome scientists and reviewing newer data, the 10% idea looked increasingly flawed. When you examine how the oral environment and mineral particles behave, you realize: more isn’t always better.
Too much nano-hydroxyapatite (nHA) can hinder performance. A new peer-reviewed, Fygg-funded study—published in the Journal of Dentistry (2025)—provides controlled lab data that explains why a lower concentration, optimized at the particle level, can outperform higher concentrations of lower-quality material.
That in vitro study evaluated eight major remineralizing toothpastes, including fluoride, nano-HAP, micro-HAP, and a notable “10% nano-HAP” brand. The authors observed that Fygg’s superior performance likely derived from enhanced physicochemical properties rather than mere concentration. In some comparisons, superior results also related to Fygg’s higher concentration of NanoXIM in its formulation.
Impressively, Fygg’s toothpaste performed comparably to prescription-strength fluoride toothpaste—the clinical gold standard for remineralization, typically only available with a prescription and sold at a significant premium.
Why more isn’t better
Adding more nHA does not guarantee better outcomes. High concentrations can promote aggregation—particles clump into larger chunks that do not disperse well across enamel, lowering bioavailability and reducing the material’s ability to penetrate subsurface lesions and reverse early decay.
The Journal of Dentistry (2025) notes: “Particle size and formulation design appear to play a pivotal role in the therapeutic outcome… The superior efficacy of Fygg was likely due to its optimized particle morphology and lower concentration of nanoXIM.”
That quote reflects a core point: particle size, shape, surface properties, and formulation matter. We designed our product to maintain nHA suspended in saliva so teeth can take it up efficiently. If particles clump, they behave like undissolved solids in liquid—less available to interact with tooth surfaces.
NanoXIM is a proprietary nHA blend engineered to a specific size and rod-shaped morphology—smaller than 50 nm—aimed at mimicking natural enamel structure for ideal surface binding and uptake.
Why the 10% claim is outdated
The 10% figure traces back to earlier studies (2009 and 2011) conducted when nano standards were less defined. At that time, 10% was the lowest concentration at which crude nHA samples showed a measurable effect. Since then, advances in particle engineering, purity, and characterization have changed the landscape.
Today, morphology, surface charge, and delivery medium are far more important than raw concentration. Many products still use micro-sized HAP particles, which are taken up far less efficiently than properly engineered nano particles. Larger particles—especially those exceeding about 1.3 μm—adhere poorly to enamel, while well-controlled nano particles show stronger surface binding and better functional outcomes.
Fygg’s approach uses a 20% NanoXIM paste that contains 15.5% nHA, yielding a 3.1% total active nHA in the final toothpaste—a concentration that the study demonstrated can outperform some products that claim a full 10% nHA when those products use less optimal particle preparations.
When I set out to develop a toothpaste, I wanted a fluoride-free alternative that truly worked. That required collaboration with chemists, researchers, and oral microbiome experts to find the balance that would:
- Penetrate subsurface lesions to increase the depth of remineralization
- Prevent aggregation so nHA remains available and effective
- Support the oral microbiome, which plays a key role in natural remineralization
The peer-reviewed study confirms what lab scientists and formulation experts expected: optimized nano particle properties and proper formulation can deliver stronger remineralization even at lower active concentrations.
Biological systems have optimal ranges. Just like pH balance or oxygen levels, there’s a “sweet spot” for particles in saliva—too much or too little reduces effectiveness. The goal is the right amount suspended in saliva so teeth can access it when needed.
I’m proud Fygg prioritized science when designing this product, and grateful to the researchers who validated the approach.
Here’s to better science, healthier mouths, and fewer clumps in your toothpaste.
Dr. B
P.S. Know someone repeating the 10% myth? Forward this to them — and if they’d like future updates, they can sign up for the newsletter.