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Leakproof UltraThin No-Show Boybrief
Leakproof UltraThin No-Show Boybrief
$34.00
USD
Buy 3+ Save 15%, Buy 5+ Save 20%
Absorbs about 2.5 super tampons
Invisible under clothes
Moderate protection without the bulk
Machine washable
Size and Fit Guide
How to Measure
In order to select the correct sizing, we recommend you take the following measurements using a soft tape measure. If necessary, ask someone else to help.
Waist
Measure around the narrowest part of your torso, usually just above your belly button. Keep the tape snug and level, but not tight. The number where it meets is your waist measurement.
Hip
Stand with your feet together and measure around the fullest part of your hips and buttocks. Keep the tape level and snug, but not tight. The number where it meets is your hip measurement.
Build Your 3-Pack
Leakproof UltraThin No-Show Boybrief
Leakproof UltraThin No-Show Boybrief
Leakproof UltraThin No-Show Boybrief
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Product Description
Comfort-First Fit
Worry-Free Protection
Our newest leakproof innovation provides more absorbency without the bulk. Patented 360 LeakSeal™ technology locks in leaks at every edge.
Moderate Absorbency
Absorbs 2.5 super tampons worth of liquid—perfect for moderate flow days, light bladder leaks, and sweat. The carbon cotton gusset top layer keeps you dry.
No-Show Style
Buttery-soft and smooth fabric gives a seamless look and feel. Disappears under clothes, even leggings.
Easy to Wash
Machine washable just like regular underwear.
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How to Choose?
Essential
- • Days you don’t need leak protection. Everyday freshness and moisture wicking.
-
0 tsp
Heavy
- • Extra peace of mind. For the first days of your cycle, light bladder leaks, or a full night's sleep without a leak.
-
about 8-14 tsp
-
about 1.5-3 regular pads
-
about 4-7 super tampons
-
about 1.5-3 menstrual cups
Light
- • Daily freshness. For sweat, discharge, period spotting, or backup protection.
-
about 1-3 tsp
-
about 1-3 pantyliners
-
about 1-3 regular tampons
-
about 0.5 menstrual cups
Moderate
- • For mid-cycle flow, surprise cough or sneeze leaks, or a really sweaty spin class.
-
about 4-8 tsp
-
about 1-1.5 regular pads
-
about 2-4 super tampons
-
about 0.5-3 menstrual cups
Ultra
- • Ultimate peace of mind. For the heaviest period days, light bladder leaks, unexpected postpartum flow, or overnight protection.
-
about 15-20 tsp
-
about 1.5-2.5 super pads
-
about 7-11 super tampons
-
about 2-3 menstrual cups
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FRESH FIX TECHNOLOGY®
Built-in protection that feels like nothing at all.
Our patented 360 LeakSeal™ technology locks in leaks at every edge. The ultra-thin liner absorbs about 2.5 super tampons worth of liquid.
Soft Top Layer
Middle Layer
Leakproof Layer
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How to wash
Knix underwear is 100% reusable and machine washable, just like your regular undies.
Not required. But for best results, you can rinse your leakproof with cold water in the tub or sink before washing.
Machine wash on a cold, gentle cycle with mild detergent.
For their longest life, air drying is best. Hang or lay flat to dry.
Fabric softeners, bleach, ironing, or heat from the dryer.
Total 5 star reviews: 143 Total 4 star reviews: 11 Total 3 star reviews: 7 Total 2 star reviews: 7 Total 1 star reviews: 2
What our customers are saying
Generated by AI from 100 most recent customer reviews
Last updated 3 weeks ago
Customers say these boybrief underwear are exceptionally comfortable and provide excellent coverage without riding up. They appreciate the ultra-thin design that remains invisible under clothing, including jeans and yoga pants, with no visible panty lines. Users find the fit perfect for various body types and praise the soft, lightweight fabric that feels like a second skin. Many mention the confidence and security these provide, with several customers becoming repeat purchasers across multiple colors. Common feedback includes requests for more color options and lighter flow levels. A few customers note concerns about recent design changes, including new seams and fit issues, while some mention the waistband can roll down during sleep.
91%would recommend this product
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Rating
170 reviews
- Rated 4 out of 5 stars30 minutes agoI love it 😊!
Good quality
KUKnix US 2.027 seconds agoHey Chin!
Thanks so much for taking the time to review our Leakproof UltraThin No-Show Boybrief! We're so happy to hear you're loving the quality 💖
Team Knix
Chin T.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 2 out of 5 stars2 days agoNot enough coverage
For a plus size person we need more coverage. I like the feel and materials but the coverage isn’t there in regards to the belly.
Sara A.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars3 days agoPERFECT!
I now have 8 pairs of the Leakproof Ultra Thin No-Show Boybrief, and will continue to purchase when new colors come out. They are THE most comfortable undies I've ever had - you barely know you're wearing any. I HIGHLY recommend!
Lorie C.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars5 days agoIn Love
Love these briefs. so comfortable. great fit
Dawn W.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars1 week agoLeakproof Ultra Thin Boybrief
I like the set. One thing I didn’t realize when ordering is the pad sewn into the gusset. They fit and are comfortable.
Wendy C.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars1 week agoMy new favorite
I love the fit of the Boybriefs. A little more coverage than the Knix Boy shorts.
Lisa B.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars1 week agoCulotte garçonne
J'aime beaucoup ce sous-vêtement. On a l'impression de rien porter et il reste bien en place.
Françoise S.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars1 week agoNo show boy brief
Wonderful
Terry M.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars1 week agoLove the cut!
I like the cut of these - can wear as a waist high full behind coverage rather than as a low waist shorts style (as in the photo). Am not a fan of less than full butt coverage. Don't need the level of leak proofing, but bought for the style.
Cathie D.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars2 weeks agoGreat comfortable underwear
Love how much coverage these have. I do wish they came in a light leakproof instead of medium leakproof strength, as I'd love to save a little money on them and do not need the higher strength, just the higher coverage. They are super comfortable and very durable through washes.
Dayna E.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars2 weeks agoPerfect fit
These are the most comfortable of all of the Knix underwear
that I have purchased. The seams don't show when I wear
legging for workouts and the gusset stays in place.
Theresa R.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief - Rated 5 out of 5 stars2 weeks agoBoybrief
Love the new boybrief. Fit really well. Comfy.
Lynn M.Verified BuyerReviewingLeakproof UltraThin No-Show Boybrief
