Absorbency Guide: How to Find the Right Period Underwear for Your Flow
Just like us, our products are constantly evolving. Launching a whole new period care category over a decade ago was no easy feat—and neither is challenging ourselves to innovate and redefine those same products everyday. This is all, of course, with the aim of helping you feel uninhibited on your period, so you can live unapologetically free (from bulky underwear).
Whether you’re a period underwear enthusiast or novice, we’re here to help you find the best period underwear for your lifestyle and flow. Ahead is everything you need to know about our absorbency classifications and which styles best suit whatever phase of life you're in.
Oh, and psst, if the packaging on your glossy new undies doesn’t totally match up to this guide—don’t worry, we’re working on that.
Light Absorbency 🩸
For your lightest period days—you know, when you’re spotting and kind of just want to forget you’re on your period altogether—there’s Light Leakproof Underwear. This range is designed to be your best friend on light flow days and can be worn with tampons and menstrual cups as backup leak protection. To that we say: go ahead and wear the white pants.
Absorbency: Absorbs 1.5-3 tsps of menstrual fluid, discharge, and sweat—which is about the equivalent of 1-3 regular tampons.
Styles:
- Light Leakproof No-Show Mesh High Rise.
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Light Leakproof No-Show High Rise, Bikini, Thong and Boyshort.
- Light Leakproof No-Show French Cut.
Best for: Wearing solo when you’re spotting, backup protection on regular flow days, and mildly sweaty workouts.
Moderate Absorbency 🩸🩸🩸
Looking for more than just backup protection? For regular flow days, there’s period underwear that can be worn solo all-day long (or as a backup when your flow is heavier). If you want all the absorbency but none of the bulk.
Absorbency: Absorbs 2-4 super tampons worth of menstrual fluid, sweat, and urine.
Styles:
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Leakproof UltraThin No-Show Bikini, French Cut, and High Rise.
- Leakproof UltraThin Mesh High Rise.
- Leakproof CoreLove High Rise.
- Leakproof No-Show Thong.
Best for: Wearing solo on medium flow days, backup protection on heavy flow days, and light bladder leaks.
Heavy Absorbency 🩸🩸🩸🩸
If we had a dime for every time we soaked through bedsheets or our favorite pair of pants, our bank accounts would all have an extra comma. Super Leakproof period underwear styles were designed with heavier flow days in mind—because who wants to wake up early to change their tampon?
Absorbency: Absorbs 4-7 super tampons of menstrual fluid, sweat, and urine.
Styles:
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Super Leakproof No-Show Bikini, Boybrief, High Rise, and French Cut.
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Super Leakproof Dream Short.
- Super Leakproof Dream Boxer.
- Super Leakproof Cotton Bikini, High Rise, Boybrief, and Boxer Brief.
Best for: Your period’s heavier days, overnight protection for sweet dreams, and sneaky bladder leaks when you cough or sneeze.
Ultra Absorbency 🩸🩸🩸🩸🩸
Our ultra absorbent period underwear are not messing around when it comes to leak protection. These heavy-duty styles leave period and bladder leaks shaking in their boots. And for good reason—this is our most absorbent assortment of period underwear to date, featuring extended coverage zones for targeted protection where you need it most.
Absorbency: Absorbs 7-11 super tampons of menstrual fluid, sweat, and urine.
Styles:
Best for: Wearing solo on your heaviest period days (and nights), as well as light bladder leaks during postpartum, menopause, and life’s other phases.
PS: if you’re ever staring into your underwear drawer wondering which pair is which—you’re not alone. Once they’re out of the packaging, here’s a quick way to tell them apart: UltraThin styles have the branded Knix tape around the entire gusset (front, back, and sides). Light Leakproof pairs only have that tape along the sides. And when it comes to our Super and Ultra absorbency styles, you’ll notice they feel a bit thicker and have a longer gusset for extra coverage where it counts.
A little design detective work goes a long way—and soon enough, you’ll be able to spot your go-to pair without a second thought. Take our Leakproof Quiz to find your perfect pair!
