Hydroxyapatite Toothpaste and the Pineal Gland: The Facts

We have seen questions online about hydroxyapatite toothpaste, pineal gland calcification, and whether particles from toothpaste can enter the bloodstream or brain.

They are fair questions to ask. There is a lot of information online, but not all of it reflects how the body works or what the evidence shows.

The simple answer is this: there is no evidence that hydroxyapatite toothpaste causes hydroxyapatite to build up in the pineal gland.

What is hydroxyapatite?

Hydroxyapatite is a calcium-phosphate mineral naturally found in teeth and bones. It makes up most of the mineral part of tooth enamel, which is why it is used in oral care.

In toothpaste, hydroxyapatite is designed to work on the surface of teeth. It can help replenish minerals in areas of enamel affected by everyday acid exposure.

At TruthPaste, we use micron-sized hydroxyapatite with an average particle size of around 1.5 microns, or 1,500 nanometres.

This is not nano-hydroxyapatite. Nanomaterials are generally defined as materials with particles in the size range of 1 to 100 nanometres. Our hydroxyapatite is substantially larger than this range (Komiyama et al., 2019).

Why particle size matters

We chose this particle size deliberately.

Our hydroxyapatite is large enough to be classed as non-nano, while still being small enough to work closely with the microscopic surface structure of teeth. It can coat exposed dentine and support the occlusion of open dentine tubules, the tiny channels within dentine that can contribute to tooth sensitivity when exposed.

Research shows that hydroxyapatite toothpastes can help occlude dentine tubules. The exact degree of occlusion depends on factors including particle size, the formula itself, brushing habits, and the condition of the tooth surface (Yuan et al., 2019).

Our focus is simple: using an enamel-compatible mineral where it is needed, on the teeth.

Could hydroxyapatite enter the bloodstream?

For hydroxyapatite from toothpaste to reach the pineal gland, it would first need to enter the bloodstream in a meaningful amount as intact particles.

There are two possible routes: through the lining of the mouth, or by being swallowed and passing through the digestive system.

The lining of the mouth is not a significant route for hydroxyapatite particles to enter the body. The European Commission’s independent Scientific Committee on Consumer Safety reviewed nano-hydroxyapatite and concluded that uptake through the buccal membrane, the lining of the cheek, is negligible. It found that any particles taken up by superficial cells would leave the body as those cells are naturally shed and replaced (SCCS, 2025).

This conclusion is also supported by a laboratory study using three-dimensional oral tissue models. Even when nano-hydroxyapatite was tested at much higher and longer exposures than would occur during normal brushing, it did not penetrate into the deeper layers of the oral tissue. The researchers concluded that it was very unlikely to enter the bloodstream or systemic tissues through intact oral mucosa (Komiyama et al., 2019).

Small amounts of toothpaste can be swallowed during brushing. In the acidic environment of the stomach, hydroxyapatite dissolves into calcium and phosphate ions. These are normal dietary minerals, found in food and water, which the body regulates carefully.

This is very different from intact hydroxyapatite particles travelling through the bloodstream and depositing in an organ.

Calcium, food and context

Calcium is an essential mineral. The body uses it every day to support bones and teeth, normal muscle function, nerve signalling, and many other basic processes.

We get calcium from many sources, including food, water, and supplements. You would not rule out calcium-rich foods simply because you had heard that calcium-based deposits can sometimes occur in the brain.

The same principle applies to hydroxyapatite toothpaste.

Hydroxyapatite is a calcium-phosphate mineral used to support teeth. The fact that calcium-phosphate minerals can also be found in naturally occurring pineal deposits does not mean hydroxyapatite from toothpaste travels there or causes those deposits.

It is a little like saying that drinking milk causes calcium to build up in the brain because milk contains calcium. Similar minerals can be found in different parts of the body without one causing the other.

What about pineal calcification?

The pineal gland can naturally develop small calcium-based deposits over time. These are often called corpora arenacea, or “brain sand”.

They are common findings on brain scans and become more frequent with age. A systematic review and meta-analysis estimated the pooled prevalence of pineal calcification at around 62%, although this varies between populations, age groups, and imaging methods (Belay and Worku, 2023).

These deposits are made mainly from calcium and phosphorus compounds. However, this does not mean that they have come from food, drinking water, supplements, or toothpaste.

The body handles calcium and phosphate continuously. These minerals are essential to normal biology, and their presence in more than one part of the body does not show that they have travelled from one place to another.

There is no credible evidence that hydroxyapatite toothpaste causes pineal calcification or makes it worse.

What about nano-hydroxyapatite?

You may see claims online that nano-hydroxyapatite can cross the blood-brain barrier. This is not the most useful way to consider toothpaste and pineal-gland concerns.

The key question is whether hydroxyapatite from toothpaste reaches the bloodstream in meaningful amounts in the first place. Current evidence does not support this happening through healthy oral tissue during normal toothpaste use.

The Scientific Committee on Consumer Safety reviewed specified forms of nano-hydroxyapatite for oral-care use. In its 2025 opinion, it concluded that the material assessed was safe at concentrations of up to 29.5% in toothpaste and up to 10% in mouthwash (SCCS, 2025).

This finding applies to the specific nano-hydroxyapatite materials assessed, with defined particle characteristics and use conditions. It does not mean every nanoparticle is the same, or that findings from nanoparticles specially designed for medical drug delivery apply to toothpaste.

At TruthPaste, we use non-nano, micron-sized hydroxyapatite.

The bottom line

Hydroxyapatite in toothpaste is there for your teeth, not your pineal gland.

Our hydroxyapatite has an average particle size of 1.5 microns. It is non-nano, designed to work on the tooth surface, and small enough to support the occlusion of exposed dentine tubules.

Pineal calcifications are naturally occurring calcium-phosphate deposits that are common, particularly with age. There is no evidence that hydroxyapatite toothpaste causes them.

We believe oral care should be simple: thoughtful ingredients, clear information, and no unnecessary fear.

References

Belay, D.G. and Worku, M.G. (2023) ‘Prevalence of pineal gland calcification: Systematic review and meta-analysis’, Systematic Reviews, 12, 32. Available at: https://doi.org/10.1186/s13643-023-02205-5

Komiyama, S., Miyasaka, R., Kikukawa, K. and Hayman, R. (2019) ‘Can nano-hydroxyapatite permeate the oral mucosa? A histological study using three-dimensional tissue models’, PLOS ONE, 14(4), e0215681. Available at: https://doi.org/10.1371/journal.pone.0215681

Scientific Committee on Consumer Safety (SCCS) (2025) Scientific Opinion on Hydroxyapatite (nano), Submission IV. SCCS/1677/25. European Commission. Available at: https://health.ec.europa.eu/publications/sccs-scientific-opinion-hydroxyapatite-nano-submission-iv_en (Accessed: 10 August 2026).

Yuan, P., Liu, S., Lv, Y., Liu, W., Ma, W. and Xu, P. (2019) ‘Effect of a dentifrice containing different particle sizes of hydroxyapatite on dentin tubule occlusion and aqueous Cr(VI) sorption’, International Journal of Nanomedicine, 14, pp. 5245-5256. Available at: https://doi.org/10.2147/IJN.S204086