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Leakproof UltraThin No-Show Bikini
#1 Daytime Solution
Leakproof UltraThin No-Show Bikini
$27.00
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 Bikini
Leakproof UltraThin No-Show Bikini
Leakproof UltraThin No-Show Bikini
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Product Description
Comfort-First Fit
Bikini silhouette with a classic mid-rise fit, medium hip and bum coverage.
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 your 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
Recently Viewed
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: 521 Total 4 star reviews: 85 Total 3 star reviews: 46 Total 2 star reviews: 33 Total 1 star reviews: 42
What our customers are saying
Generated by AI from 100 most recent customer reviews
Last updated 3 months ago
Customers say these period underwear are comfortable and provide excellent protection without the bulkiness of traditional pads. Many appreciate the thin, no-show design that works well under clothing and the stylish patterns like polka dots. Users frequently mention the confidence and peace of mind these provide during periods, workouts, and daily activities. Several note they're particularly good for teens and lighter flow days. However, common concerns include sizing inconsistencies, with many finding recent purchases run smaller than expected. Some mention the front coverage could be longer, and a few experience issues with leg holes being too tight. Despite sizing challenges, most customers praise the comfort, absorbency, and quality of the product.
86%would recommend these products
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How do you use your Leakproof?
Usual Pant Size
727 reviews
- Rated 4 out of 5 stars3 minutes agoGreat leakproof
I wear them for light bladder leaks. Menopausal so no more periods. They work really well for that purpose. They are also no-show. The only issue I have is they don’t stay in place as well as I would like. I am unfortunately getting some wedgies with loose clothing.
WKWendy K.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Last Call - Rated 5 out of 5 stars9 hours agoLeakprrof UltraThin No-Show Bikini 3-pack
Great panties ... would recommend!
MDMonique D.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Last Call - Rated 5 out of 5 starsYesterdayLove them!
Love using Knix as a backup, and with UltraThin, I don’t feel like I’m wearing a diaper.
LNLindsay N.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Last Call - Rated 4 out of 5 stars2 days agoUltrathin
Very comfy but slightly drape off
NANancy A.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Last Call - Rated 5 out of 5 stars4 days agoLeakproof Ultra thin bikini
Great fit, smooth. No worries of the little leaks!
ABAudrey B.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Last Call - Rated 5 out of 5 stars5 days agoLove, love, love them
The ultra thin no-show is sooo comfortable that you don't even realize that you have them on. These are my favorite.
RGRobyn G.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Last Call - Rated 5 out of 5 stars5 days agolove love love it!!!
always as I expect it, correct sizing and fabric make it my go-to
JMJude M.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Last Call - Rated 5 out of 5 stars1 week agoLeakproof backup
I use these alone some days and other days as backup. They usually last a year or more depending on whether I dry them a lot or hang them to dry.
ARAshley R.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Last Call - Rated 2 out of 5 stars1 week agoSizing
These fit smaller than the bikinis in cotten or the briefs. They squeeze my body. Maybe sized wrong? Cotten one is underneath. Maybe I’ll loose weight?
RHRobin H.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Last Call - Rated 5 out of 5 stars1 week ago5 Stars
Interesting pattern -I love the leakproof bikini. The new improvements to the gusset are fantastic! They last longer! Now I need a new reason to buy new patterns. 😉
KKirstenReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars1 week ago5 Stars
Purples are my favorite color. I love adding this hue! I wear the leakproof bikini exclusively.
KKirstenReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars1 week agoLoved the No-Show Bikini
Fit so comfortably and I didn't leak at all!
LCLana C.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini
