Join Our Rewards Program
Earn rewards and exclusive member-only benefits for free.
Leakproof UltraThin No-Show Bikini - Last Call
Last Call
Leakproof UltraThin No-Show Bikini - Last Call
$18.90
USD
$27.00
30-40% off
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.
Rewards Members Earn
18 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 your 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
Recently Viewed
Explore Best-Sellers
Shop All
Restocked
Super Leakproof® Mini Dream Boxer
$48.00
USD
Buy More, Save More
Color: Blue Stripe Polka Dot Limited Edition
+2
Flash Sale ⚡
Revolution V-Neck Bra
$48.75
USD
25% off
Color: Black
+4
Super Leakproof® Dream Short™
$42.00
USD
Buy More, Save More
Color: Twilight Navy
+1
Flash Sale ⚡
Uplift Push Up Bra
$51.00
USD
25% off
Color: Warm Sand
+2
Flash Sale ⚡
Catalyst Sports Bra
$58.50
USD
25% off
Color: Zebra Limited Edition
+1
Total 5 star reviews: 499 Total 4 star reviews: 82 Total 3 star reviews: 46 Total 2 star reviews: 31 Total 1 star reviews: 42
What our customers are saying
Generated by AI from 100 most recent customer reviews
Last updated 2 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
Pant Size
Usage
Pant Size Purchased
700 reviews
- Rated 5 out of 5 stars36 minutes agoLove
So good, comfy and wash so well
KUKnix US 2.04 minutes agoHey Kenneth!
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 how well they wash!
Team Knix
Kenneth M.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars2 days agoMust buy
These undies exceeded expectation. They fit true to size and are genuinely comfortable. I have tried other period underwear brands and have found them all very uncomfortable and oddly tight around the legs. These fit like normal underwear. 10/10 recommend
KUKnix US 2.02 days agoHey Rachel!
This is amazing! We're so happy our UltraThin No-Show Bikini exceeded your expectations and feels like normal underwear. There's nothing better than hearing our customers feel comfortable in their Knix!
Team Knix
Rachel G.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 1 out of 5 stars3 days ago3wks and have received nothing yet but get multiple daily emails asking me to review product I have not received.
Title is self explanatory. May be a good product I wouldn’t know. Shipping sucks though.
Nicole E. C.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 4 out of 5 stars3 days agoloose on legs
Beautiful fabric & perfect for a sneeze leak. My only problem I had is that the leg band is very loose, so it sits half way up my cheek.
KUKnix US 2.03 days agoHey Jane,
Thanks for your feedback! We're glad the fabric and protection work well for you. We appreciate you mentioning the leg band fit - we'll share this with our team!
Team Knix
JaneVerified ReviewerReviewingLeakproof UltraThin No-Show Bikini - Last Call - Rated 3 out of 5 stars3 days agoCute and functional!
I got three pairs of these in different designs. Super cute, but a little disappointed with fit. I previously purchased XXXL and they've always been a bit too big, then I lost about ten pounds and just needed the nice size down. Unfortunately, around my legs is quite tight, so a bit uncomfortable. Leak wise, they're amazing. Would give 3.5 stars if I could.
Madison R.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 4 out of 5 stars4 days agoI love them
I love them!! I’m so happy Knix exists
KUKnix US 2.04 days agoHey Georgia!
This made our day! We're so thrilled you're loving our Leakproof UltraThin No-Show Bikini. There's nothing better than hearing our customers feel amazing in their Knix!
Team Knix
Georgia a.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars5 days agoThese are perfect for me!
The bikini is the best for me. The fit is great and the ultra thin is the way to go.
KUKnix US 2.05 days agoHey Gina!
Thanks so much for the amazing review! We're thrilled to hear the UltraThin No-Show Bikini is your perfect fit. You nailed it with the ultra thin choice!
Team Knix
Gina M. P.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars6 days agoGreat
Pretty much need these leakproof’s for most of the month with post and pre cycle lingerings! The amount of liners not in the landfill thanks to these undies makes me happy
KUKnix US 2.06 days agoHey Kerrin!
We love hearing how our Leakproof UltraThin No-Show Bikinis are keeping you comfortable all month long while helping the planet too! Thanks for choosing Knix!
Team Knix
Kerrin B.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Rated 5 out of 5 stars1 week agoSo comfortable and worry free!
I recommend!
KUKnix US 2.01 week agoHey Susan!
Thanks so much for the recommendation! We're thrilled to hear our Leakproof UltraThin No-Show Bikini is keeping you comfortable and worry-free!
Team Knix
Susan S.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars1 week agoBikini review
White underwear with blue print
Lorna M.Verified BuyerReviewingLeakproof UltraThin No-Show Bikini - Rated 5 out of 5 stars1 week ago5 Stars
Love the bikini ultra thins. Have around 25 pair and they hold up extremely well!
SuzanneReviewingLeakproof UltraThin No-Show Bikini 3-Pack - Rated 4 out of 5 stars2 weeks agoA bit too small but wonderful underwear
I bough the XXL high rise and they are wonderful, but a bit too large for me, should have taken XL. The back is way high so sometime it shows with my pants. Then, I bough the bikini one XXL, and these ones are a bit too small, should have taken XXXL So not sure about sizing when ordering as they seem different depending on style. BUT they are amazing. Im 5'9", 200 pounds
KUKnix US 2.02 weeks agoHey VegaOfLyra,
Thanks for the feedback! We're glad you love the underwear quality. Sizing can vary by style - we'll share your insights with our team to help improve consistency!
Team Knix
VegaOfLyraVerified ReviewerReviewingLeakproof UltraThin No-Show Bikini
