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Teen Leakproof UltraThin No-Show Bikini

$24.00 USD

Buy 3+ Save 15%, Buy 5+ Save 20%

Absorbs about 2.5 super tampons

Invisible under clothes

Superior protection without the bulk

Machine washable

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Color: Black

Size:

True to Size

Size:

Size and Fit Guide

Build Your 3-Pack

Teen Leakproof UltraThin No-Show Bikini

Color: Black

Size:

Size:

Teen Leakproof UltraThin No-Show Bikini

Color: Black

Size:

Size:

Teen Leakproof UltraThin No-Show Bikini

Color: Black

Size:

Size:

Free Shipping on orders $100+

Shipping

Shipping

Processing Timelines

Please allow 1-2 business days for our warehouse team to pack and ship your order. During peak periods such as sales, holidays and product launches, please allow up to 4 business days for us to process your order. Once an order is placed, we cannot guarantee any address updates, order changes or cancellations. Orders placed on Friday after 1PM will not be shipped until the following Monday.


Split Shipments

Most orders will ship from a single warehouse. However, we occasionally ship from a combination of warehouse locations, so you may receive your order in multiple parts. If items from your order ship in separate packages, we’ll send you tracking information for each package when it becomes available.

Delivery Timelines

For the most up-to-date delivery time estimates, please refer to the shipping timeline at checkout. Delivery timelines do not include processing times. See above for details. All transit times are measured in business days which are Monday-Friday, excluding holidays.

Please note, all shipping timelines are estimates and are not guaranteed.

We are not able to ship to US territories (including Puerto Rico, U.S. Virgin Islands, Guam, Northern Mariana Islands and American Samoa) at this time.

First Pair Risk Free for 30 Days

Leakproof Underwear, Risk Free

Returns & Exchanges

New to leakproof? Your first pair is risk free for 30 days. Wear them, wash them, and see how they work for your body. Not right for you? We'll refund the item price (original shipping excluded). Prefer a different size or style? We also offer free exchanges. Just email info@knix.com and we'll take care of you.

Purchased leakproof before? Within 30 days of delivery you can exchange for another size, style, or store credit. We're unable to provide refunds on underwear. If you ordered multiple pairs, please open, wash, and wear one pair only before initiating an exchange.

Still have questions? View our full policy here.

Rewards Members Earn 24 Points

Product Description

Hanging out or running to your next class? These period undies provide the ultimate comfort you want, plus ultra-thin protection you need from sweat, discharge and leaks. It’s a classic silhouette made with a super soft-and-stretchy, quick-drying material. It absorbs about the equivalent of 2.5 super tampons for an extra dose of confidence on those medium-flow days.

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 More Panty Lines

Made from our signature buttery-soft fabric and designed to be invisible under clothes, including leggings.

Easy to Wash

Machine washable just like regular underwear.

Zoom

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How to Choose?

Essential

  • Days you don’t need leak protection. Everyday freshness and moisture wicking.
  • tsp
    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.
  • tsp
    about 8-14 tsp
  • pad
    about 1.5-3 regular pads
  • tampon
    about 4-7 super tampons
  • cup
    about 1.5-3 menstrual cups

Light

  • Daily freshness. For sweat, discharge, period spotting, or backup protection.
  • tsp
    about 1-3 tsp
  • pad
    about 1-3 pantyliners
  • tampon
    about 1-3 regular tampons
  • cup
    about 0.5 menstrual cups

Moderate

  • For mid-cycle flow, surprise cough or sneeze leaks, or a really sweaty spin class.
  • tsp
    about 4-8 tsp
  • pad
    about 1-1.5 regular pads
  • tampon
    about 2-4 super tampons
  • cup
    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.
  • tsp
    about 15-20 tsp
  • pad
    about 1.5-2.5 super pads
  • tampon
    about 7-11 super tampons
  • cup
    about 2-3 menstrual cups
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

Gently wicks away moisture while keeping you feeling fresh and odor-free.

4.4
Rated 4.4 out of 5 stars
Based on 745 reviews
Total 5 star reviews: 547 Total 4 star reviews: 81 Total 3 star reviews: 46 Total 2 star reviews: 30 Total 1 star reviews: 41
What our customers are saying
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
ComfortRated 4.5 on a scale of 1 to 5
FitRated -0.1 on a scale of minus 2 to 2
EffectivenessRated 4.6 on a scale of 1 to 5
Keywords
Keywords
Rating
Ratings
Height
Height
Usual Pant Size - Knixteen
Usual Pant Size - Knixteen
Size Purchased - Knixteen Underwear
Size Purchased - Knixteen Underwear
745 reviews
  • Rated 5 out of 5 stars
    1 hour ago
    Amazing

    Can't say enough about these panties. They absolutely deliver what is promised. So comfortable it feels like you are wearing nothing!!

    On those hot and humid days when you are working out or working hard these are the best to wick away that unwanted moisture.

    Dianna N.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    4 hours ago
    Awesome leakproof

    Love my no show leakproof panties.

    Meryana V.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    23 hours ago
    Perfect feel and fit

    These are my favorite undies!

    Jill J.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 3 out of 5 stars
    Yesterday
    Bladder leak protection is minimal

    I was looking for a prettier panty with some leak protection. I only used the. for an evening out and they overflowed. To be fair Knix did not recommend this for bladder protection.

    Diana S.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 4 out of 5 stars
    2 days ago
    Comfortable

    Thin and comfortable

    Kacie S.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    5 days ago
    Comfortable, Effective, & Cute

    So comfortable and cute!

    Lisa A.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    5 days ago
    I love the pattern

    These are so pretty and so comfortable. Lovely to wear on the tail end of your period.

    Lisa A.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 2 out of 5 stars
    5 days ago
    Wishing they were seamless

    I wish you had seamless underwear. The underwear rubs on my hubs and is very rough

    Erin P.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    6 days ago
    5 Stars

    My daily go-to for comfort and protection

    Kirsten
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    6 days ago
    5 Stars

    I love this new pattern. It’s so pretty and whimsical! I’ve been buying these leakproof for a few years and they work great. I like the improvements they’ve made to strengthen the gusset.

    Kirsten
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    1 week ago
    Favorite!

    These are my favorite underwear. After trying several different brands, these are now the only underwear I wear. I appreciate the protection that the leakproof gives and it allows for more confidence in any outfit knowing that they have a liner that is leakproof. They are soft and very comfortable. They also launder well.

    Elaine C.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 1 out of 5 stars
    1 week ago
    Poor fit

    I have ordered before for my daughter but not for myself. I do not like the way these fit me at all. I'm so disappointed that now I feel like I have to keep them even though they don't fit because it's just the cut and I don't trust a different style and I don't want a different style. And there are no refunds. I rushed to get these before running a quarter Marathon and I have major regrets..

    Brooke B.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini