PFAS score
Thinx · Period Underwear
Thinx Intimates & Sleepwear Thinx for All Women's Period Underwear
Higher PFAS risk due to waterproof coating; brand silent on composition, skip until transparency improves.
Period underwear requires moisture-wicking and waterproofing, which commonly rely on water-repellent coating (water-repellent coating) coatings, a known source of PFAS exposure. Thinx does not publicly disclose coating materials or provide PFAS testing results.
The safe swap
JAMA Organic
LOLA Organic Cotton Period Underwear
100/100 safety
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Nylon, spandex, cotton blend with waterproof barrier layer
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Waterproof / stain-resistant treatment
water-repellent coating treatments have historically used PFAS.
Category baseline
period care is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 55% confidence. It is not a lab result.
No independent PFAS lab test is on record for this exact product. A lab test could move the score in either direction.
The brand has not made a specific, verifiable PFAS-free statement, so part of this score reflects that missing disclosure rather than a confirmed material.
Formulations and coatings change between production runs. Always check the current label before buying.
Safer alternatives in Period Underwear
JAMA Organic
LOLA Organic Cotton Period Underwear
Organic cotton with moisture-wicking gusset
Lower PFAS concern, organic cotton base with no waterproof claims, but brand doesn't explicitly address PFAS.
✓Verified PFAS-free by a third party
JAMA Organic
Organyc Certified Organic Cotton Disposable Period Underwear for Sensitive Skin
certified organic cotton with absorbent core
Lower concern, organic cotton base suggests minimal PFAS risk, but no explicit PFAS statement limits confidence.
✓Verified PFAS-free by a third party
Ruby Love
Women's Hipster Period Underwear
organic cotton with waterproof coating
Lower concern, PFAS-free verified; buy with confidence.
✓Lab test found no PFAS
More period underwear grades
How we score: every product runs through the same public 0–100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.