nanoXIM toothpaste: what nanoXIM·CarePaste is, and how to check for it

Last checked: November 2026. Written by Clockwork, which uses nanoXIM·CarePaste under licence from FLUIDINOVA.

The short answer

nanoXIM·CarePaste is a named nano-hydroxyapatite ingredient made by FLUIDINOVA in Portugal. Hydroxyapatite is the mineral tooth enamel is made of. nanoXIM·CarePaste supplies it as rod-shaped, uncoated nano particles in a paste, ready to go into a toothpaste. A "nanoXIM toothpaste" is a toothpaste that uses it, and a brand that does can name the maker.

The specification

What it is Nano-hydroxyapatite, Ca₁₀(PO₄)₆(OH)₂, in an aqueous paste
Maker FLUIDINOVA, Portugal
Shape Rod-shaped and uncoated: the form Europe's Scientific Committee on Consumer Safety assessed for toothpaste (SCCS/1648/22, 2023)
Size Nano, median length 27.6 nm
Registration EU REACH 01-2119490075-38-0021
What it does in a toothpaste Settles on the enamel surface and helps remineralise enamel

Why the name matters

"Contains hydroxyapatite" doesn't tell you the shape, the size or who made it, and those decide which safety assessment applies. A named ingredient does: you can look up its maker, its registration and its specification. That is why we print "nanoXIM·CarePaste" and "FLUIDINOVA" on our pack rather than just "nano-hydroxyapatite". Why the source comes before the percentage →

How to tell if a toothpaste uses nanoXIM·CarePaste

  1. The pack or listing names nanoXIM·CarePaste and FLUIDINOVA.
  2. It states how much nanoXIM·CarePaste is in the tube, and makes clear that the percentage is of nanoXIM·CarePaste.
  3. The brand can show the REACH registration and the particle specification if you ask.

Which Clockwork toothpastes use it

  • Clockwork Daily: 10% nanoXIM·CarePaste, plus 10% xylitol. Fluoride free, SLS free. ₹575.
  • Enamel Reserve: 20% nanoXIM·CarePaste. Coming soon.

See Clockwork nHAp toothpaste →

Questions people ask

Is nanoXIM the same as nano-hydroxyapatite?

nanoXIM is FLUIDINOVA's name for its hydroxyapatite products. nanoXIM·CarePaste is the grade made for oral care. All of it is nano-hydroxyapatite, but not all nano-hydroxyapatite is nanoXIM.

Does 10% nanoXIM·CarePaste mean 10% hydroxyapatite?

No. The 10% is of nanoXIM·CarePaste, the paste that carries the mineral. Always ask what a percentage on a toothpaste refers to.

Has nanoXIM·CarePaste been studied?

Yes, in laboratory and clinical studies of toothpastes that contain it. None of them tested Clockwork. See the studies on hydroxyapatite toothpaste, with their limits →

nanoXIM and nanoXIM·CarePaste are trademarks of FLUIDINOVA, S.A., used under licence.