style + fit
A barely-there fit for lighter days — in cozy organic cotton.
buy more + save more
Mix and match any undies from Thinx, Thinx (BTWN), or Speax — and save a li’l $$$!
“The Cotton Thong is a great daily complement to a menstrual cup. The fit is great and I feel protected from any possible leaks.”
Alexis from Dunwoody, GA, light to heavy flow
period underwear that works
fabric
body 95% organic cotton, 5% elastane
gusset 95% cotton, 5% elastane; middle breathable PUL
Our underwear has been successfully tested for harmful substances and certified according to STANDARD 100 by OEKO-TEX®️ [20.HUS.04850 | HOHENSTEIN HTTI]
care instructions
To take care of your Thinx, give ‘em a spin in the washing machine on cold (just no softener or bleach!), and hang dry. Do not iron!
XXS
XS
S
M
L
XL
XXL
3XL
cups
pads | liners
discs
other
light
moderate
heavy
FAQs
What is your return policy?
We offer free returns and exchanges within 60 days of purchase, no questions asked! Just visit the Thinx Inc. Return & Exchange Center to get started.
How do Thinx work?
Thinx are underwear that absorb your period. Every pair is made with a patented design and our signature technology that absorbs your flow, wicks moisture, controls odor, and prevents leaks — leaving you fresh and dry. Take a look at our How it Works page to learn more.
How long can I wear Thinx?
We measure our undies by absorbency with our highest absorbency styles holding 4 tampons worth of fluid. For some customers, that means wearing them the whole day and for others that may mean carrying an extra pair of Thinx as a backup. If you have more questions, please try our Know Your Flow quiz.
How do I know what size to buy?
We recommend following the hip measurement, as most of our styles sit on the hips. Be sure to measure your hips at their widest point (derriere included!) to find the most accurate size for you! In case you don't have a tape measure, you can use the size you usually are most comfortable with for your underwear. We recommend the undies fit snuggly, but not so tight that it's uncomfortable. For reference, you can check out our Thinx size chart.
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