Leakproof UltraThin No-Show Bikini
Mix & Match: Buy 4+ Save 15%, 7+ Save 25%
Knix period underwear and pads are now sales tax-free in Canada.* We celebrate improvements to the accessibility and affordability of essential period care products.
• Our newest leakproof innovation provides more absorbency without the bulk.
• Great for leak protection, the ultra-thin liner absorbs about the same as 2.5 super tampons or 1 regular pad’s worth.
• Our patented 360 LeakSeal™ technology locks in leaks at every edge.
• The carbon cotton gusset top layer wicks away moisture from your skin.
• These underwear feature our signature buttery soft fabric.
• No-show construction is designed to be invisible under clothes, including workout leggings.
• Machine washable just like regular underwear.
Get the protection you want from periods and light bladder leaks while feeling comfortable and worry-free.
• Classic mid-rise silhouette
• Medium hip & bum coverage
• Ultra-thin, built-in liner
• Absorbs about 2.5 super tampons’ worth of liquid
• Quick dry gusset
• Soft, stretchy PerformaStretch® fabric
• Conforms to your body
The fabric is designed to feel snug at first but relax with wash and wear for a perfect fit.🇨🇦 Free standard shipping over $100.
Free expedited shipping over $150.
(after discounts, before shipping + taxes) All items ship from within Canada.
Within 30 days of delivery, you may exchange for another size, style or store credit. We’re unable to provide refunds on underwear.
How to wash
Machine Washable: Wash with like colors, cold setting with mild detergent, do not bleach, iron, or dry clean.
Always refer to our Fabric & Care section for best drying practices.
Our Absorbency Guide
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.
*Period underwear and pads are exempt from federal sales tax in Canada. They are also exempt from most provincial / harmonized sales taxes. But are subject to the following provincial sales tax rates which will apply to orders shipped to the following provinces and to orders purchased in retail stores located in the following provinces: British Columbia and Manitoba: 7% PST; Saskatchewan: 6% PST.
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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!
- Jess P.Verified Reviewer38 minutes agoRated 5 out of 5 starsWhere are my 40-something mamas?!
These are seriously the best leak proof underwear on the market. I’m 40 and after my third baby, my pelvic floor is a mess. While I’m getting PT I needed something to help during my HIIT workouts and my half marathon training and these are fantastic! I wish these were around when I was younger because I can definitely see how they support you during heavier day periods. I ordered a Medium and they fit perfectly but I’m a true medium and not in between sizes. If you’re on the fence about trying these out, I highly recommend! Thank you, Knix!
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? - Susan S.Verified Buyer2 hours agoRated 5 out of 5 starsGreat quality
Great material very comfortable
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? - Sandra C.Verified BuyerI'm a... Parental FigureI purchased for... A Teenager/TweenPant Size Teen 00-2Size Purchased XSUsage Primary Protection9 hours agoI'm a... Parental FigureI purchased for... A Teenager/TweenPant Size Teen 00-2Size Purchased XSUsage Primary ProtectionRated 5 out of 5 starsRevolutionary Feminine Protection
KT by Knix period underwear has been an absolute game-changer for my teen! As a dancer, she needs to feel confident and comfortable while performing, and traditional pads and liners just weren’t cutting it—they were bulky, uncomfortable, and constantly shifting. I started looking for alternatives and came across KT by Knix. After ordering a couple of pairs to try, she was immediately sold!
These are true to size, super comfortable, incredibly absorbent, and most importantly—completely leakproof. Whether she’s at practice, in class, or on stage, she can focus on dancing without worrying about leaks or discomfort. The confidence and peace of mind these provide are priceless! I highly recommend them to any parent looking for a reliable and comfortable period solution for their active teen.
QualityRated 5.0 on a scale of 1 to 5Poor ExcellentComfortRated 5.0 on a scale of 1 to 5Poor ExcellentSizingRated 0.0 on a scale of minus 2 to 2Fits Small True to Size Fits LargeEffectivenessRated 5.0 on a scale of 1 to 5Poor ExcellentWas this helpful?