A white bowl filled with clear plastic retainers beside a steel spoon

Microplastics · 3 min read

Your retainer may be your #1 source of microplastics.

We put plastic retainers through six months of simulated chewing. Each pair shed about 59,000 microplastics, roughly doubling the microplastics the average adult eats and breathes in a year. Every night you wear one, you're eating plastic.1, 2

Make The Clean Switch

Microplastics: no longer a “maybe.”

It’s already inside us

Microplastics aren’t just an environmental problem. They’re in our blood,11 lungs,12 placentas,13 brains14 and breast milk.15 Every human tissue scientists have tested so far has come back contaminated. In diseased tissue from people with IBD,16 dementia17 and heart disease,7 microplastic levels are significantly higher than in healthy tissue.

The trajectory is clear

Every new study finds higher concentrations in human tissue than the last. Most recently, researchers found a 50% increase in microplastics in brain tissue over eight years.17 What we take in today stays with us for decades, and the next generation is born contaminated. That’s before counting nanoplastics, which we couldn’t even detect until about ten years ago.14

What the mice tell us

Mice exposed to higher doses develop gut inflammation,18 hormone disruption,19 infertility,20 developmental delays21 and organ damage.22 Their doses are higher than ours, for now. The global plastic load keeps climbing, and the gap is closing.

Humans can’t afford 1% of that

Even a fraction of those effects showing up in people would be a global health crisis. Mice don’t live 80 years, carry nine-month pregnancies, or build up plastic for decades. We do.

Waiting for regulators before acting is the mistake we made with lead, asbestos and PFAS. Let’s not make it again. Start with the plastic you put in your mouth every night.

About 59,000 particles per pair. Every six months.

Most clear retainers are PETG, a cousin of fossil-fuel-based plastic, worn eight hours a night: warm, wet and under pressure. We took PETG retainers to the dental materials testing facility at the University at Buffalo and ran them through a chewing simulator built to mimic a human bite. Then independent labs counted what came off.1

58,2401
chews at about 11 lb of force, at body temperature. Six months of nightly wear.
~59,0001
plastic particles shed per pair, each confirmed as PETG.
3.4 mg1
of plastic gone from every pair. Every retainer showed wear.
Water from the chewing test seen through the bottom of a jar, full of white specks of retainer plastic
Water from our chewing test. Every white speck is retainer plastic. And that’s an undercount: anything under 15 microns wasn’t counted.

What that means for you

One retainer can double your yearly dose.

The most widely cited estimate puts the average American at roughly 100,000 microplastic particles a year from food and air.2 Our test puts one year of retainer wear at about 118,000.1

Make The Clean Switch
A hand holding the clear moses Unplastic Retainer

A retainer made without petroleum plastic.

The moses Unplastic Retainer is made from pure PHA, a material microbes make from sugar. It holds your teeth like the one you wear now, without leaving persistent plastic behind.

  • Breaks down into a molecule your body already makes. In a simulated gut, PHA digested within weeks; PETG barely changed.1
  • Nothing added: no plasticizers, colorants, clarifiers or stabilizers.
  • Screened for 82 contaminants. Phthalates, PFAS and bisphenols: not detected.10
Pure material: 100% PHA, no plasticizers, stabilizers, colorants or chemical clarifiers. Every batch lab tested for contaminants. Built to break down, not to stay in you. A new pair ships before your current one wears out.
The clear Unplastic Retainer on a blue saucer beside a glass of water and an open stainless steel travel case

The Unplastic Retainer

Stop eating plastic

A custom-fit upper and lower pair made from pure PHA. Same fit you’re used to, without the persistent microplastics.

Make The Clean Switch

Sources

  1. Westlie, A. H. Microplastic release from orthodontic retainers during simulated wear. moses white paper, 2026. Lab simulation, not a human study; the per-year figure is a linear extrapolation.
  2. Cox, K. D. et al. Human consumption of microplastics. Environ. Sci. Technol. 2019 (corrected 2020). doi
  3. Warunek, J. et al. Orthodontic-derived microplastics impact macrophage differentiation and homeostasis. Prog. Orthod. 2026. doi
  4. Hussain, K. A. et al. Release of micro- and nanoplastics from plastic containers. Environ. Sci. Technol. 2023. doi
  5. Snekkevik, V. K. et al. Sources of microplastic contamination in home kitchens. Heliyon 2024. doi
  6. Tang, K. H. D. Counteracting the harms of microplastics on humans. Microplastics 2025. doi
  7. Marfella, R. et al. Microplastics and nanoplastics in atheromas and cardiovascular events. N. Engl. J. Med. 2024. An association, not proof of cause. doi
  8. Nihart, A. J. et al. Bioaccumulation of microplastics in decedent human brains. Nat. Med. 2025. Its measurement methods have been debated. doi
  9. Barile, C. et al. Damage and microplastic release during cyclic loading of clear aligners. PLoS One 2025. doi
  10. Independent contaminant screening by Light Labs, batch RMPHA26001B1. Full results and raw lab reports.
  11. Leslie, H. A. et al. Discovery and quantification of plastic particle pollution in human blood. Environ. Int. 2022. PubMed
  12. Jenner, L. C. et al. Detection of microplastics in human lung tissue. Sci. Total Environ. 2022. PubMed
  13. Ragusa, A. et al. Plasticenta: first evidence of microplastics in human placenta. Environ. Int. 2021. PubMed
  14. Human brain tissue microplastics and nanoplastics study, 2024. PubMed
  15. Ragusa, A. et al. Raman microspectroscopy detection of microplastics in human breastmilk. Polymers 2022. MDPI
  16. Yan, Z. et al. Analysis of microplastics in human feces and patients with inflammatory bowel disease. Environ. Sci. Technol. 2022. PubMed
  17. Nihart, A. J. et al. Bioaccumulation of microplastics in decedent human brains. Nat. Med. 2025. PubMed
  18. Gut inflammation in mice exposed to microplastics. 2024. PubMed
  19. Hormone disruption in mice exposed to microplastics. Part. Fibre Toxicol. 2022. Article
  20. Reproductive effects of microplastics in mice. 2022. PubMed
  21. Developmental effects of microplastics in mice. Front. Physiol. 2023. Article
  22. Organ damage in mice exposed to microplastics. Sci. Total Environ. 2021. Article
  23. Mouse studies use higher doses than typical human exposure; results in animals don’t prove the same effects in people.

This page is for information only and isn’t medical advice. Keep wearing your retainer as prescribed, and talk to your dentist or orthodontist with any questions.