Products are split into three levels based on ingredient labels

GO
Best choice
SLOW
Contains ingredients with possible health concerns
STOP
Contains harmful ingredients
STOP

Thinx

Period Underwear

Last verified: April 29, 2026

  • Polyamide
  • Elastane
  • Supima Cotton
  • Lenzing Micro Modal
  • Polyurethane Laminate (PUL)
  • Polyester

Why This Product is Rated STOP

Period Underwear by Thinx has been evaluated by Million Marker and contains ingredients with known health concerns. This product is rated STOP, indicating higher concern.

We recommend avoiding STOP-rated products and seeking safer alternatives from our GO or SLOW categories.

Learn more about how Million Marker scores products →

Frequently Asked Questions

Period Underwear by Thinx - Non-toxic Period Care product rated STOP by Million Marker, free from BPA, phthalates, and parabens

Where to buy

Thinx Google Search