Thinx Hi-Waist Period Underwear
Summary
Thinx Hi-Waist scores 22/100. In 2022 Thinx agreed to a $4 million class-action settlement after independent testing detected PFAS (forever chemicals) and silver nanoparticles in their gusset — directly contradicting their 'non-toxic' marketing claims. The brand was subsequently acquired by Kimberly-Clark (parent of Kotex, Huggies, Depend), the same disposables conglomerate this app's clean-feminine-care entries are designed to provide alternatives to. While Thinx now publishes 'reformulated' PFAS-free claims, no independent third-party verification has been made publicly available post-settlement, and customer trust collapsed for valid reasons. The outer fabric is 95% cotton, but the proprietary moisture-wicking lining remains undisclosed. Significantly worse track record than every other period-underwear brand on this list.
At a glance
Key ingredients 5
Cotton Outer (95%)Good
Cotton outer shell is one structural positive. Not specified as organic on most styles.
See more about Cotton Outer (95%) →Elastane (5%)Neutral
Synthetic elastic for fit retention.
See more about Elastane (5%) →Proprietary Moisture-Wicking LiningVery Bad
Composition is not publicly disclosed. In 2020 independent testing detected per- and polyfluoroalkyl substances (PFAS / forever chemicals) and silver nanoparticles in the gusset, leading to a $4 million class-action settlement in 2022. Thinx claims post-settlement reformulation but has not published independent third-party test results to substantiate this.
See more about Proprietary Moisture-Wicking Lining →Historical PFAS ContaminationVery Bad
Class-action confirmed detectable per- and polyfluoroalkyl substances in product despite explicit 'non-toxic' and 'free of harmful chemicals' marketing claims. These compounds bioaccumulate, persist in the environment, and are linked to endocrine disruption, immune dysfunction, and certain cancers.
See more about Historical PFAS Contamination →Kimberly-Clark Corporate Ownership
Acquired by Kimberly-Clark (Kotex, Huggies, Depend, Scott) post-settlement. Corporate parent's mainstream feminine-care brands score poorly on this app for fragrance and bleached-pulp concerns.
See more about Kimberly-Clark Corporate Ownership →Get the full breakdown in the Scout app
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