Nano-Hydroxyapatite Toothpaste and Safety: What the European Review Found
Some toothpastes sold in the United States contain hydroxyapatite in nano-sized particles. Patients ask whether particles that small can enter the body, and whether they can reach the brain. This article states what the main safety review found, and what it did not cover.
What was reviewed
The Scientific Committee on Consumer Safety (SCCS) advises the European Commission on the safety of cosmetic ingredients. It reviewed hydroxyapatite (nano) in several opinions. Its 2023 opinion judged a specified material safe at up to 10 percent in toothpaste and up to 0.465 percent in mouthwash. A 2025 opinion assessed a different specified material at up to 29.5 percent in toothpaste and 10 percent in mouthwash. The two assessments used different particle specifications, and neither is a blanket approval of all rod-shaped particles. A 2024 European regulation then introduced legal limits for the material in oral cosmetic products, following the 2023 assessment. A scientific opinion and a legally permitted concentration are different things. [1][2][3]
Each conclusion applies only to the material specified in that opinion: particles meeting a stated size and shape specification, not coated and not surface-modified, used in toothpaste or mouthwash at the stated concentrations. [1][2]
What the review found about entry into the body
The committee found that uptake of the particles through the lining of the mouth is negligible, and that the small number of cells that do take up particles are shed in the normal course of cell turnover. It found that particles swallowed during brushing dissolve rapidly in stomach acid, into calcium and phosphate. On that basis it concluded that swallowed particles do not raise a nano-specific safety concern. [2]
That statement should be read with its limits attached. It describes the specified materials, at the assessed concentrations, by the assessed route. It is not a finding about every nano-hydroxyapatite product sold.
What the review did not cover
- Needle-shaped particles. Needle-shaped material is not covered by these safety conclusions. [1]
- Sprays. Products that can be inhaled were not covered, because no inhalation data were submitted. [1]
- Products outside the assessed specification. The conclusion belongs to the material that was submitted and characterized. A product made with particles of a different shape, size, or coating is not covered by it.
The position in the United States
In the United States, a toothpaste that makes no drug claim is regulated as a cosmetic. Cosmetics do not require FDA approval before sale. The manufacturer is responsible for the safety of the product and must have adequate evidence to support that safety, under the Modernization of Cosmetics Regulation Act of 2022. [4][5] A U.S. product label may not provide enough information to establish whether its particles match the assessed material.
Summary
For the specified materials, at the concentrations assessed, the European review found negligible uptake through the mouth lining and rapid dissolution of swallowed particles in stomach acid, and judged the materials safe in toothpaste and mouthwash. These safety conclusions do not cover needle-shaped particles or inhaled products, and they do not transfer automatically to products whose particles have not been characterized. Patients who are concerned can choose a product that states its particle specification, or a fluoride toothpaste, which has a longer record of both effectiveness and safety review. Our post on fluoride in drinking water reviews the evidence for fluoride itself in full.
These findings are reassuring for the materials and conditions assessed, but they do not establish the safety of every formulation or its effectiveness at preventing cavities.
Evidence matters. Individual assessment matters. If you are using a hydroxyapatite toothpaste and want to review it with us, bring the product to your next visit, and let’s talk.
The scientific and regulatory information in this article was reviewed on November 1, 2026.
References
- Scientific Committee on Consumer Safety (SCCS). Opinion on Hydroxyapatite (nano), SCCS/1648/22. European Commission. 2023. European Commission
- Scientific Committee on Consumer Safety (SCCS). Opinion on Hydroxyapatite (nano), Submission IV, SCCS/1677/25. European Commission. 2025. European Commission
- Commission Regulation (EU) 2024/858, introducing legal limits for hydroxyapatite (nano) in oral cosmetic products. EUR-Lex
- U.S. Food and Drug Administration. Is It a Cosmetic, a Drug, or Both? FDA
- U.S. Food and Drug Administration. Modernization of Cosmetics Regulation Act of 2022 (MoCRA). FDA