Join Our Rewards Program
Earn rewards and exclusive member-only benefits for free.
ACOTAR™ Leakproof Ultrathin™ No-Show Bikini Box Set
ACOTAR™ x Knix
ACOTAR™ Leakproof Ultrathin™ No-Show Bikini Box Set
$115.00
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.
Estimated Shipping: Oct 21-30
Get It Before It's Gone
ACOTAR™ x Knix
Get It Before It's Gone
Rewards Members Earn
115 Points
You May Also Like
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
Perfect for moderate period days, light bladder leaks, and sweat. Moisture-wicking liner keeps you dry and comfortable.
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.
Zoom
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
ACOTAR™ x Knix Collection
Shop All
ACOTAR™ x Knix
Super Leakproof® Dream Short™
$42.00
USD
Buy More, Save More
Color: Velaris Night Sky Limited Edition
ACOTAR™ x Knix
Leakproof UltraThin™ No-Show High Rise 3-Pack
$80.00
USD
Save $21
Color: Ink That Binds/Midnight/Velaris Night Sky Limited Edition
ACOTAR™ x Knix
Revolution V-Neck Bra
$65.00
USD
Buy 2 Bras Get 15% Off
Color: Velaris Night Sky Limited Edition
ACOTAR™ x Knix
Super Leakproof® Dream Boxer™
$48.00
USD
Buy More, Save More
Color: Ember Fox Limited Edition
ACOTAR™ x Knix
Leakproof UltraThin™ No-Show Bikini
$27.00
USD
Buy More, Save More
Color: Spring Court Bloom Limited Edition
ACOTAR™ x Knix
Satin Lace Trim Cami & Short Set
$78.00
USD
Color: Spring Court Bloom Limited Edition
ACOTAR™ x Knix
Full Length Satin Robe
$115.00
USD
Color: Spring Court Bloom Limited Edition
ACOTAR™ x KNIX
Choose your Court. Choose your fantasy.
Explore the limited-edition collection of intimates, sleepwear, and apparel inspired by the characters who rule the realm.
The Night Court
The Spring Court
The Summer Court
The Autumn Court
The Fan Court Collection
Shop All
ACOTAR™ x Knix
ACOTAR™ Leakproof Ultrathin™ No-Show Bikini Box Set
$115.00
USD
Color: Thorns & Roses/Mist & Fury/Wings & Ruin/Frost & Starlight/Silver Flames Limited Edition
ACOTAR™ x Knix
Cotton Relaxed Graphic T-Shirt
$50.00
USD
Color: Darling White Limited Edition
ACOTAR™ x Knix
Oversized Graphic T-Shirt
$55.00
USD
Color: Book Boyfriend Washed Grey Limited Edition
ACOTAR™ x Knix
Graphic Crewneck Sweater
$95.00
USD
Color: Cursebreaker Black Limited Edition
ACOTAR™ x Knix
Graphic Cropped Hoodie
$115.00
USD
Color: Cursebreaker Ivory Limited Edition
ACOTAR™ x Knix
Tote Bag
$25.00
USD
Color: Cursebreaker Ivory Limited Edition
ACOTAR™ x Knix
Crew Embroidery Socks 2-Pack
$25.00
USD
Color: Rose and Flame Black/White Limited Edition
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
Search
Keywords
Rating
Height
How do you use your Leakproof?
Usual Pant Size
782 reviews
- Rated 3 out of 5 stars12 hours agoQuality is great, fit is not.
As always, Knix provides great quality items. I just found this particular style is too low rise on my body. Unfortunately the material slips, and in turn I find myself constantly adjusting to pull back up. I will in the future stick with high rise only.
LDLindi D.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 starsYesterdayDancing Drier
I am well past my period days, but I attend dance class and socials 4-5 nights a week, 2-3 hours a night. Let's just say, things get pretty sweaty down there. My dance pants can be pretty form fitting and, besides the discomfort of wet pants (ew), I didn't want to look like I'd peed my pants. I thought I 'd give your panties a try for dance nights. I loved them so much, I bought a bunch more.
DSDeborah S.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 starsYesterdayGreat product!
Great product!
VEVeronika E.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 4 out of 5 starsYesterdayLove the Design and Performance!
⭐⭐⭐⭐
I really love these! The Autumn Court theme is my absolute favorite. 🍂✨ They’re super comfortable and work amazingly well! The only reason I’m giving them four stars instead of five is that I find the fit a little snug. Other than that, I’m really happy with them! Honestly, I don’t know why I haven’t tried these sooner!
MSMikaela S.Verified BuyerReviewingLeakproof UltraThin™ No-Show Bikini 3-Pack - Rated 5 out of 5 stars3 days ago5 Stars
love them awesome packaging
LLeahReviewingACOTAR™ Leakproof Ultrathin™ No-Show Bikini Box Set - Rated 5 out of 5 stars3 days agoGet them! Life changing..
I wish I bought these years before I did. I’ve had 8 pairs on serious repeat for 3 years. I just bought 6 more (acotar night court, yes please!) Hang to dry & they last. Haven’t spent a dollar on landfill liners since these & a cup for heavy days. Think of the money you’ll save! Invest!
LGLanessa G.Verified BuyerReviewingLeakproof UltraThin™ No-Show Bikini 3-Pack - Rated 5 out of 5 stars4 days agoBest Underwear Ever
My entire collection is Knix and i don’t regret it. They make my days more manageable and I feel more confident knowing im protected no matter what.
KFKayla F.Verified BuyerReviewingLeakproof UltraThin™ No-Show Bikini 3-Pack - Rated 5 out of 5 stars5 days agoAmazing
Both my teen daughters love these. They are 13 and 15
TMTiffany M.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 3 out of 5 stars5 days agoFit
Fit a little snug
LDLeila D.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars5 days agoAcotar collection
Absolutely loved this collection and this set was so super comfortable! This was my first set and was so happy with it
ASAlexandria S.Verified BuyerReviewingLeakproof UltraThin™ No-Show Bikini 3-Pack - Rated 5 out of 5 stars6 days agoThe best product
My favorite underwear
TNTiffany N.Verified BuyerReviewingLeakproof UltraThin™ No-Show Bikini 3-Pack - Rated 5 out of 5 stars1 week 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
