Leakproof Cotton Boybrief
30% off






Leakproof Cotton Boybrief
30% off
• Great for daytime protection, the ultra-thin liner absorbs about the same as 3 super tampons or 1.5 regular pads worth of liquid.
• The innovative floating gusset provides leak protection from every angle.
• The cotton-spandex blend feels luxurious against your skin.
• Certified according to OEKO-TEX® STANDARD 100, Product Class I : HK020 246396 TESTEX
• Machine washable just like regular underwear.
Get the protection you want from periods and light bladder leaks while feeling comfortable and worry-free.
• Brief shorts style
• Absorbs the same as about 3 super tampons’ worth of liquid
• Quick dry liner
• Soft, cotton-spandex blend
Body: 96% Cotton/Coton, 4% Spandex; Fresh Fix Technology® Gusset: Gusset 1: 92% Polyester, 8% Spandex; Gusset 2: 95% Polyester, 5% Spandex; Gusset 3: 100% Polyester; 100% Thermoplastic Polyurethane
Additional Product Ingredient Information
🇺🇸 Free standard shipping over $100*.
Duty-free. (after discounts, before shipping + taxes)
EXCHANGE ONLY Items on sale during our Anniversary Sale are exchange only. For items with a 20% or more discount you may exchange for another item or store credit. No refunds.
Your leakproof questions, answered.
Our Leakproof technology features a built-in absorbent liner. Depending on the style you choose, the absorbency can range from about 1-17 tsp of liquid. The result? Confident protection from sweat, discharge, periods, and light bladder leaks.
A gusset is essentially a liner. It’s where you’ll find our leakproof technology. It’s built into the crotch section of the underwear.
Coverage at Knix comes in all shapes and sizes. If we’re talking about silhouettes, we go all the way from thongs to boxers.
We also offer high rise styles, like the Leakproof UltraThin No-Show High Rise, that sits just above the natural waist and gives full coverage through the stomach, hip & bum.
For extra liner coverage, look for undies that have an “extra-long liner” (usually 10”-14”), like in our Dream Short. And our Ultra Zones+ also have full bum coverage, too.
Have a suggested style or coverage? Just let us know. We love the feedback!
Many people refer to them as period underwear or period panties. But leakproof underwear covers you for all of life’s leaks, including periods (even your heaviest flows), sweat, light bladder leaks, postpartum, and discharge.
- KATHERINE1 hour agoRated 5 out of 5 stars5 Stars
A gamechanger!
Was this helpful? - Pamela M.Verified Buyer2 days agoRated 5 out of 5 starsGame changer
I will never wear a pad again! Thank goodness for this amazing alternative. Soft and comfortable.
ComfortRated 5.0 on a scale of 1 to 5Poor ExcellentEffectivenessRated 5.0 on a scale of 1 to 5Poor ExcellentSizingRated 0.0 on a scale of minus 2 to 2Runs Small True to Size Runs LargeWas this helpful? - Tanya C.Verified Buyer6 days agoRated 5 out of 5 starsFull cotton boybrief
Love very comfortable great fit
ComfortRated 5.0 on a scale of 1 to 5Poor ExcellentEffectivenessRated 5.0 on a scale of 1 to 5Poor ExcellentFitRated 0.0 on a scale of minus 2 to 2Runs Small True to Size Runs LargeEase of UseRated 5.0 on a scale of 1 to 5Poor ExcellentWas this helpful?