Nano vs. Micro Hydroxyapatite: What’s the Difference?

If you’ve already made the switch to fluoride-free toothpaste, you’re ahead of the curve. But have you looked closely at which type of hydroxyapatite you’re using?

Hydroxyapatite is gaining attention as the best alternative to fluoride for strengthening enamel, but it comes in two forms: nano and micro. While they sound similar, the difference in size, sourcing, and safety is significant. In this guide, we break it all down to help you make the best decision for your smile and your family’s health.

Why Hydroxyapatite Is Replacing Fluoride

Hydroxyapatite is a naturally occurring mineral that makes up 97% of tooth enamel and 70% of bone. Unlike fluoride, which hardens teeth from the outside in, hydroxyapatite actually rebuilds lost minerals from within, making it both effective and biocompatible.

It’s also:

• Non-toxic
• Safe if swallowed
• Ideal for children, pregnant individuals, and those with chemical sensitivities

These qualities have made it the leading ingredient in fluoride-free toothpaste. But not all hydroxyapatite is created equal.

Nano vs. Micro Hydroxyapatite: What’s the Difference?

Nano Hydroxyapatite

• Size: Particles smaller than 100 nanometers
• Performance: Can penetrate deeper into enamel pores
• Source: Often synthetically derived
• Use Case: Frequently used in whitening and clinical formulas
• Concerns: Potential for absorption into tissues; long-term safety under review

Micro Hydroxyapatite

• Size: Larger than 100 nanometers (closer to natural enamel crystal size)
• Performance: Bonds to enamel surface for gentle, sustained repair
• Source: Can be naturally derived: Terra & Co. uses a vegan, mineral-based micro hydroxyapatite
• Use Case: Ideal for daily brushing and family-friendly care
• Benefits: Safer particle size, trusted by holistic dentists, supports microbiome health

Ingredient Labels Don’t Always Tell You the Type

Many brands list "hydroxyapatite" without specifying whether it’s nano or micro. But if you’re aiming for clean-label, holistic wellness, or if you’re buying for your kids, that distinction matters.

At Terra & Co., we go further by using:

• Micro Organic Vegan Source Hydroxyapatite
• Sourced from minerals, not synthesized in a lab
• Biocompatible, microbiome-safe, and naturally effective

Is One Better Than the Other?

It depends on your needs, but here’s what we’ve found:

While nano hydroxyapatite may offer fast-acting remineralization, micro hydroxyapatite offers a safer, slower, and more natural approach that supports whole-mouth wellness.

Why Terra & Co. Chooses Micro

We use Micro Organic Vegan Source Hydroxyapatite in both our Gentle Green and Brilliant Black® toothpaste formulas because:

• It's safe to swallow
• It aligns with clean-label and cruelty-free standards
• It supports remineralization without compromising the oral microbiome
• It’s trusted by holistic and functional dentists

Our goal is simple: create effective products that work for real people, especially families who don’t want to sacrifice safety for performance.

Final Thoughts

Hydroxyapatite is one of the most exciting developments in oral care, but knowing the difference between nano and micro matters. For ingredient-conscious consumers, the safest path is clear: micro hydroxyapatite offers effective enamel repair without the unknowns of nano-scale absorption.

Whether you're switching from fluoride or upgrading your holistic routine, Terra & Co.’s micro hydroxyapatite toothpaste delivers gentle, clean, daily protection, sourced from nature, not a lab.