Period Care Reviewed Jul 5, 2026

Thinx

The period-underwear pioneer — bought by Kimberly-Clark, and it settled a PFAS class action.

Settlement · 2023 · resolved

PFAS class-action settlement (Dickens v. Thinx)

After independent testing (Sierra Club / Dr. Graham Peaslee, 2020) detected PFAS "forever chemicals" in Thinx period underwear despite its non-toxic marketing, a class action (Dickens v. Thinx) settled in 2023 for up to ~$5M. Thinx denied wrongdoing and agreed to take measures to ensure PFAS are not intentionally added to its products.

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Our take

Why It’s on Our Radar

We don't recommend it as a clean pick. It's conglomerate-owned and settled a class action after independent testing found PFAS in products marketed as non-toxic. It's here as a cautionary reference, with founder-owned, PFAS-tested alternatives above.

What's inside

Ingredients & Safety

Marketed as non-toxic, but independent 2020 testing detected PFAS "forever chemicals," and the brand settled a class action over it in 2023 (agreeing to steps to avoid intentionally-added PFAS going forward).

We read every line on this label. Nothing here is on our watch or caution list — no synthetic fragrance, no flagged chemicals.

Full Ingredient List

Safe Watch Caution
  • Nylon
  • Elastane
  • Cotton Lining

Prefer a spotless pick? Natracare in Period Care is Clean Verified — every ingredient clean, with no recalls or lawsuits on record.

Who owns it

Ownership & Independence

Kimberly-Clark acquired a majority stake in Thinx in 2022 and completed the acquisition in 2024. Thinx is no longer independent.

Where to buy

Key Products

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