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: the price of the specific style you want, sizing that runs differently than the brands you may be coming from, and stock that comes and goes. 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 a current style, its claim is "up to 12 regular tampons' worth" - about 108 mL on the FDA regular-tampon ceiling, which is our computation, since Thinx publishes no millilitre figure for its period underwear. The closest ladder by stated 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 states up to about 99 mL, against the roughly 108 mL our table computes for Thinx's current 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?
- Some are, by a lot - The Period Company's pairs list at a fraction of Thinx's typical price - and others typically list higher, so there is no one answer. 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 capacity ceiling is the highest in our catalog, though that figure is our arithmetic on its 12-regular-tampon claim rather than a millilitre number Thinx publishes, 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 these 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.