Join Our Rewards Program
Earn rewards and exclusive member-only benefits for free.
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
Rewards Members Earn
27 Points
You May Also Like
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 regular underwear.
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
Our Best-Selling Underwear
Shop All
Restocked
Super Leakproof® Dream Boxer™
$48.00
USD
Buy More, Save More
Color: Eucalyptus Stripe Limited Edition
+1
#1 Overnight Solution
Super Leakproof® Dream Short™
$48.00
USD
Buy More, Save More
Color: Eucalyptus Limited Edition
+2
Leakproof UltraThin No-Show High Rise
$32.00
USD
Buy More, Save More
Color: Indigo Limited Edition
+5
#1 Daytime Solution
Leakproof UltraThin No-Show Bikini
$27.00
USD
Buy More, Save More
Color: Eucalyptus Limited Edition
+4
Leakproof UltraThin No-Show French Cut
$27.00
USD
Buy More, Save More
Color: Indigo Limited Edition
+2
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: 573 Total 4 star reviews: 81 Total 3 star reviews: 47 Total 2 star reviews: 30 Total 1 star reviews: 41
What our customers are saying
Generated by AI from 100 most recent customer reviews
Last updated 3 weeks 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.
87%would recommend these products
Search
Keywords
Rating
Height
Pant Size
Usage
Pant Size Purchased
772 reviews
- Rated 5 out of 5 stars35 minutes agoGreat fit, Great Product
Love the material and the invisibly of the underwear. Great protection for when you need it the most. Would 100% recommend
KUKnix US 2.04 minutes agoHey Jacqueline!
Thanks so much for taking the time to review our Leakproof UltraThin No-Show Bikini! We're so happy to hear you're loving the material and invisible feel. There's nothing better than hearing our customers feel confident in their Knix!
Team Knix
Jacqueline K.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars8 hours ago5 Stars
I love not having to wear a big bulky pad
RachelReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars8 hours ago5 Stars
Love these
RachelReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 starsYesterdayGreat
Nice fit! Do the JOB!
KUKnix US 2.0YesterdayHey Christine!
Thanks so much for taking the time to review our Leakproof UltraThin No-Show Bikini! We're so happy to hear the fit is great and they're doing the job perfectly!
Team Knix
Christine B.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 starsYesterdayComfort
There very comfortable no leaking
KUKnix US 2.0YesterdayHey Sarah!
Thanks so much for taking the time to review our Leakproof UltraThin No-Show Bikini! We're so happy to hear you're loving the comfort and leak protection. There's nothing better than hearing our customers feel amazing in their Knix!
Team Knix
Sarah G.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 starsYesterday5 Stars
I like that they are comfortable and help with bladder leaks
RachelReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars3 days agoLovely purchase
Fit nicely .
Erin R.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars5 days agoSuch a relief!
These are the best undies to not worry about any leakage or sweat! I feel dry and comfortable all day!
Carol W.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Rated 5 out of 5 stars5 days agoSave money on tampons!
This is my first time trying period underwear, and I'm a big fan! These are comfortable, reasonably priced, and the absorbency is as listed. I got the size small and they fit just fine. The only thing I'd say is that they are not truly "no-show" under tighter fitting pants as the gusset extends fairly far back. But that doesn't detract from my five stars!
Jessica M.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars5 days agoComfy and effective
Really appreciate that these don’t make me feel like I am wearing a diaper. They’re great!
Elissa M.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars6 days agoVery comfortable
Very comfortable. Just what I needed.
Anna G.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars1 week agoBikini underwear
I love them. They are so comfortable. I will diffently be buying for product from you.
Victoria W.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini
