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SuperPlus Leakproof® No-Show Bikini

$36.00 USD

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

Absorbs 7-11 super tampons

Front-to-back liner

Bonded seams prevent leaks

Machine washable

Front view of model wearing the SuperPlus Leakproof® No-Show Bikini highlighting the coverage and smooth fit

Shivani has 40” hips and wears KNIX L

SuperPlus Leakproof® No-Show Bikini shown front-facing against a light gray background
Back view of model wearing the SuperPlus Leakproof® No-Show Bikini highlighting the coverage and smooth fit

Shivani has 40” hips and wears KNIX L

Full-body view of model wearing the SuperPlus Leakproof® No-Show Bikini highlighting the coverage and smooth fit

Shivani has 40” hips and wears KNIX L

On image text: Ultra-thin, front-to-back liner. Bonded edges prevent side leaks.

Shivani has 40” hips and wears KNIX L

Color: Black

Size:

True to Size

•

Size:

Size and Fit Guide

Build Your 3-Pack

Front view of model wearing the SuperPlus Leakproof® No-Show Bikini highlighting the coverage and smooth fit

SuperPlus Leakproof® No-Show Bikini

Color: Black

Size:

Size:

Front view of model wearing the SuperPlus Leakproof® No-Show Bikini highlighting the coverage and smooth fit

SuperPlus Leakproof® No-Show Bikini

Color: Black

Size:

Size:

Front view of model wearing the SuperPlus Leakproof® No-Show Bikini highlighting the coverage and smooth fit

SuperPlus Leakproof® 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

Holiday Return Policy
Eligible items purchased online or in stores between November 2, 2026 and December 31, 2026 may be returned through January 29, 2027. All other purchases fall under our 30 day Returns Policy.

Standard Return Policy
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 36 Points

Product Description

The most absorbent invisible period panty ever made. The Knix SuperPlus Leakproof No-Show Bikini is engineered for your heaviest days, absorbing an incredible 7 to 11 super tampons’ worth of flow. Despite its massive capacity, the seamless, raw-cut edges ensure it stays completely invisible under your tightest leggings or skirts. Featuring an extra-long gusset for 360-degree security, it’s the best high-absorbency no-show underwear for those who need maximum protection without the bulk.

Comfort-First Fit

Classic mid-rise bikini silhouette with medium coverage for hips and bum.

Ultimate Leakproof Protection

Our longest, most absorbent liner ever—front-to-back coverage without the bulk.

Day & Night Comfort

Buttery-soft stretch fabric moves with you, while bonded seams keep leaks contained and create a smooth, seamless look under clothing.

Machine Washable

Wash just like your regular underwear—easy, everyday care.

Zoom

Shivani has 40” hips and wears KNIX L | Front view of model wearing the SuperPlus Leakproof® No-Show Bikini highlighting the coverage and smooth fit | Black
Shivani has 40” hips and wears KNIX L | Back view of model wearing the SuperPlus Leakproof® No-Show Bikini highlighting the coverage and smooth fit | Black
Shivani has 40” hips and wears KNIX L | Full-body view of model wearing the SuperPlus Leakproof® No-Show Bikini highlighting the coverage and smooth fit | Black

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
PATENTED LEAKPROOF TECHNOLOGY

Our longest, most absorbent liner—ever.

Our original Fresh Fix Technology® features a built-in absorbent liner that soaks up about 7–11 super tampons’ worth of liquid—so you stay fresh, comfortable, and in control.

Soft Top Layer

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

4.4
Rated 4.4 out of 5 stars
Based on 107 reviews
85%would recommend these products
FitRated -0.2 on a scale of minus 2 to 2
ComfortRated 4.5 on a scale of 1 to 5
EffectivenessRated 4.4 on a scale of 1 to 5
Keywords
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Rating
Ratings
Height
Height
How do you use your Leakproof?
How do you use your Leakproof?
Usual Pant Size
Usual Pant Size
107 reviews
  • Rated 5 out of 5 stars
    3 minutes ago
    Amazing customer service

    Knixs puts out an amazing product and on my last order I made a mistake and had them sent to the wrong address. I was not aware that I had done that so when I had not received my order due to it being delivered to the wrong address, I believe that I chatted with Catherine online she resent the order to the correct address she was amazing. Her customer service was outstanding. I cannot thank knixs enough. . I’ve been in customer service all my life and it’s so hard to find someone like her who went above and beyond

    JT
    Jennette T.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 2 out of 5 stars
    4 days ago
    Ok

    I primarily wanted these for incontinence. These will not absorb as much as I feel comfortable with counting on using alone.

    JB
    Jim B.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 5 out of 5 stars
    1 week ago
    ACOTAR !!!

    Had to get this! It’s so comfortable.

    JM
    Jazzy M.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 5 out of 5 stars
    2 weeks ago
    Comfy Fit Without Leaks

    These fit me well and hold leaks better than any othet brand I have used.

    MA
    Melissa A.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 5 out of 5 stars
    3 weeks ago
    SuperPlus Leakproof Underwear

    Just tried these out for the first time and absolutely love them! Feels like I’m not even on my period.

    HB
    Haley B.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 5 out of 5 stars
    4 weeks ago
    5 Stars

    saves me. love it so much.

    S
    Sally
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 5 out of 5 stars
    4 weeks ago
    5 Stars

    These a great if u have leaks comfortable, don’t have to have no pads they hold a lot

    A
    Anne
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 4 out of 5 stars
    4 weeks ago
    impress

    je suis impressionner, sa ne parait pas dans les jeans de porter ce type de culotte et il ny a pas de fuite, yéé

    parfait pour nos ado debutante qui ne connaisse pas encore bien leur flo

    JF
    Julie F.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 5 out of 5 stars
    1 month ago
    Perfect

    I love that the lines are pretty seamless and the closest to truly no show that I’ve found truly.

    AS
    Amanda S.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 5 out of 5 stars
    1 month ago
    Very comfortable

    I wss able to wear all day without any leaks.

    RH
    Robin H.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 5 out of 5 stars
    1 month ago
    Confortable and reliable!

    Hands down the most comfortable underwear I have ever owned. The fabric is incredibly soft, flexible and breathable. The design molds perfectly to the body without any bunching, providing completely reliable, leakproof protection that gave me total peace of mind. I absolutely love the quality and fit of the design and highly recommend it!

    AW
    Amy W.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini
  • Rated 5 out of 5 stars
    1 month ago
    Fit wonderfully,great leak proof design

    These are very comfortable and fit great plus they are super leak proof. so far not a single leak in them.I am very happy with these undies.

    SG
    Stephanie G.
    Verified Buyer
    Reviewing
    SuperPlus Leakproof® No-Show Bikini

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