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Leakproof UltraThin No-Show Bikini 3-Pack
ACOTAR™ x Knix
Leakproof UltraThin No-Show Bikini 3-Pack
$68.00
USD
Limited-edition ACOTAR™ x Knix collection
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.
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ACOTAR™ x Knix
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Part of the limited-edition ACOTAR™ x Knix Collection
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.
ACOTAR™ is a trademark of Fireheart Inc. ©2015-2026, Sarah J. Maas.
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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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Recently Viewed
What our customers are saying
Generated by AI from 100 most recent customer reviews
Last updated 5 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.
85%would recommend these products
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How do you use your Leakproof?
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753 reviews
- Rated 5 out of 5 stars2 hours agoPerfect
I love wearing these during my cycle as backup on heavy days or on their own on normal cycle days. They fit snug but not uncomfortable, so I feel secure in them and I don't have any concerns with leaks. My ONLY frustration is that on my body, they hit about 2" below my belly button, so they tend to roll down under my belly. I would love it if the waist landed a couple inches higher (but not as much as the high-rise).
ASAlexis S.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Rated 5 out of 5 starsYesterdayLove it.
Very soft and comfortable to use.
MEMary E.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars2 days agoBikini underwear
Review of bikini waterproof underwear
KKKyle K.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars2 days ago5 Stars
The are comfortable and fit perfect!
KKatherineReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars3 days agoMore comfortable than expected!
I was not expecting them to be this comfortable. They are really well cut and feel very good to wear.
MMMarie-Katherine M.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Last Call - Rated 1 out of 5 stars4 days agoLeaks
I’ve used Knix for years and love them. But for some reason this bikini design leaked blood through. Don’t get this one.
MMidVerified ReviewerReviewingLeakproof UltraThin No-Show Bikini - Rated 4 out of 5 stars5 days agoUseful bundle
I wear these when working at home and sleeping. My round behind require more coverage, but good price bundle for good quality (and nice colors). Bought many of it nevertheless! Sexier than boxers indeed! 😁
FTFrance T.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Rated 5 out of 5 stars6 days agoConfiance total
Culotté extrêmement confortable de très haute qualité confiance absolue contre les fuites . Produit bien pensé fabriqué avec des matériaux de qualité supérieure.
NDNatasha D.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars1 week agoKnix
They are soft and comfortable
CFCathy F.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars1 week agoFeels like standard bikini
The fit and comfort are beyond what I had hoped. I don't feel a difference
TMTanya M.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars1 week ago5 Stars
I love polka dots and have trouble holding my bladder, these feel great
JJessicaReviewingLeakproof UltraThin No-Show Bikini - Rated 2 out of 5 stars2 weeks agoSmaller than they were before
I got the same size (large) that I currently wear comfortably. But when I received and tried this one, it felt significantly smaller, and not looking or feeling flattering as I expect from no-show underwear. This was really disappointing, as I specifically bought this because I already had a pair bought a few years ago that I feel so good in. I don't think it's fully down to the current pair stretching out over time, as other clothes I wear fit similarly from a few years ago.
ANAnne N.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini
