The honest reasons people look past Thinx
Thinx settled a class action for up to $5 million (final court approval June 2023) over marketing its underwear as safe and non-toxic while independent testing suggested PFAS were present - without admitting wrongdoing. That history is documented, and it is also not unique: Knix settled a similar case for $1.4 million. Neither settlement was a court finding that anyone was injured. If chemical safety is your deciding factor, read our PFAS guide and weigh every brand by its current testing, not its past headlines.
The other reasons are simpler: Thinx sits at the premium end of the catalog's live prices, its sizing runs differently than the brands you may be coming from, and specific styles go out of stock. All three are visible in the live data on each pick below - price, size range, and stock come from each brand's own catalog, checked weekly.
How to compare a replacement fairly
Match millilitres, not tier names. If your Thinx pair was its flagship tier (claimed up to about 100 mL), the closest ladder by claimed maximums is Knix's Ultra tier (up to about 99 mL); most other brands top out lower, which is fine if you never needed the ceiling. Then check the size chart - every brand draws its own, so use your hip measurement, not your Thinx size. The size finder does this across every charted brand at once.
Quick answers
- What is comparable to Thinx?
- By the brands' own claims converted to millilitres, Knix reaches the closest capacity ceiling (its Ultra tier claims up to about 99 mL against the roughly 100 mL of Thinx's flagship styles). Below the very top, WUKA, Saalt, Modibodi, and The Period Company all publish tiers in the 20 to 60 mL range that cover most flows. The ranked list above shows what is actually in stock right now.
- Are Thinx alternatives cheaper?
- Usually. Thinx sits at the premium end of the live prices in our catalog; The Period Company runs a fraction of it, and most other brands land in between. Each pick above shows its current price from the brand's own store, checked weekly - compare the price against the verified millilitres to see what you are paying per unit of capacity.
- Why is there a lawsuit against Thinx?
- Thinx settled a class action for up to $5 million (final approval June 2023) over marketing claims that its products were safe and non-toxic while independent testing suggested PFAS were present. Thinx did not admit wrongdoing, and the case was about marketing versus test results - not a court finding that the products injured anyone.
- Should I still consider Thinx at all?
- That is your call, and the honest data cuts both ways: its flagship capacity claim is the highest in our catalog, and its settlement is history that the newer state laws (New York bans PFAS in period products from December 2026; California restricts intentionally added PFAS) now regulate forward. If you want Thinx compared head-to-head against a specific brand, the comparison pages do it tier by tier in millilitres.
Related guides
PFAS in period underwear: the lawsuits, the testing, and what it actually means
What PFAS "forever chemicals" are, the Thinx and Knix class-action settlements, the independent lab testing, and how to read it honestly - what was established and what was not.
What does "Heavy" mean in period underwear?
A tier labeled "Heavy" holds about 20 to 63 mL depending on the brand - a 3x spread for the same word. What it really means, brand by brand, in millilitres.
Best period underwear for heavy flow
The most absorbent period underwear for heavy flow, ranked by verified capacity in millilitres - not by the word "Heavy," which means anywhere from 20 to 63 mL depending on the brand.
Want the one-page version of the data behind our guides? The printable absorbency cheat-sheet puts every brand's tiers in millilitres on a single sheet - free, no email needed.
See every alternative with live prices
The full catalog filters by capacity and brand, with prices and stock from each brand's own store - or compare Thinx head-to-head with any brand we track.