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Home / Bikini Underwear / Super Leakproof® No-Show Bikini
New & Improved

Super Leakproof® No-Show Bikini

$29.00 USD

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

Absorbs about 6 super tampons

Invisible under clothes

Extended gusset for extra protection

Machine washable

Julie has 33.5” hips and wears KNIX S | Dark Cherry

Julie has 33.5” hips and wears KNIX S

| Dark Cherry
Julie has 33.5” hips and wears KNIX S | Dark Cherry

Julie has 33.5” hips and wears KNIX S

Julie has 33.5” hips and wears KNIX S | Dark Cherry

Julie has 33.5” hips and wears KNIX S

| General
Super Leakproof® No-Show Bikini | General

Super Leakproof® No-Show Bikini

Julie has 33.5” hips and wears KNIX S

Absorbency: Heavy

Heavy
about 4-7 super tampons
Essential
No Absorbency
Light
about 1-3 regular tampons
Moderate
about 2-4 super tampons
Ultra
about 7-11 super tampons

Color: Dark Cherry

Size:

True to Size

•

Size:

Size and Fit Guide

Build Your 3-Pack

Super Leakproof® No-Show Bikini

Color: Dark Cherry

Size:

Size:

Super Leakproof® No-Show Bikini

Color: Dark Cherry

Size:

Size:

Super Leakproof® No-Show Bikini

Color: Dark Cherry

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 29 Points

"Great coverage and fit. Love the fit, super comfy. Coverage is great, no leakage at all!"

- Lara N. M | Verified Reviewer

Product Description

Ditch the pads, keep the silhouette. Upgrade your cycle with the Super Leakproof No-Show Bikini—the perfect eco-friendly alternative to disposable products. Featuring ultra-thin technology and a buttery-soft, stretchy fabric, these bikinis offer a "barely there" feel with heavyweight performance. Whether you're at the gym or in a boardroom meeting, the moisture-wicking, anti-odor design keeps you fresh and comfortable all day long. Available in inclusive sizes XS to 4XL.

Comfort-First Fit

Classic mid-rise silhouette with provides medium hip and bum coverage.

Worry-Free Protection

Patented bonded edges help prevent side leaks.

Heavy Absorbency

Absorbs 6 Super tampons worth of liquid—perfect for heavy flow days, overnight protection, and light bladder leaks.

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

Julie has 33.5” hips and wears KNIX S | Dark Cherry
| Dark Cherry
Julie has 33.5” hips and wears KNIX S | Dark Cherry
Julie has 33.5” hips and wears KNIX S | Dark Cherry
| General
Super Leakproof® No-Show Bikini | General

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

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PATENTED LEAKPROOF TECHNOLOGY

Built-in protection that feels like nothing at all

Our original Fresh Fix Technology® features a built-in absorbent liner absorbing about 3-6 super tampons worth of liquid so you feel fresh and in-control.

Soft Top Layer

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

How to wash

Knix underwear is 100% reusable and machine washable, just like your regular undies. 

  • Rinse

    • Not required. But for best results, you can rinse your leakproof with cold water in the tub or sink before washing.

  • Wash

    • Machine wash on a cold, gentle cycle with mild detergent.

  • Dry

    • For their longest life, air drying is best. Hang or lay flat to dry.

  • Avoid

    • Fabric softeners, bleach, ironing, or heat from the dryer.

    4.6
    Rated 4.6 out of 5 stars
    Based on 2,960 reviews
    Total 5 star reviews: 2.3k Total 4 star reviews: 364 Total 3 star reviews: 138 Total 2 star reviews: 89 Total 1 star reviews: 89
    What our customers are saying
    Customers say these period underwear are comfortable and feel like regular underwear, with many praising their leak protection and confidence-boosting qualities. Users appreciate the no-show design under clothing and find them effective for both period protection and light bladder leaks. Many reviews mention the bikini cut runs small, with several customers recommending sizing up for a better fit. Some note the underwear can feel tight around the waist or create visible lines under certain clothing. While most find them durable and long-lasting, a few mention issues with the newer versions feeling stiffer or having ridges where seams meet. Overall, customers value the comfort and protection these provide as an alternative to disposable products.
    92%would recommend these products
    FitRated -0.0 on a scale of minus 2 to 2
    ComfortRated 4.6 on a scale of 1 to 5
    EffectivenessRated 4.6 on a scale of 1 to 5
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    2,960 reviews
    • Rated 5 out of 5 stars
      3 minutes ago
      It is so comfy to feel safe!

      Very comfortable and true to size. I have been using Knix period underwear for years, they are definitely worth it.

      Nadia C.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini 3-Pack
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    • Rated 5 out of 5 stars
      1 hour ago
      Does the job

      Fits great and very comfortable on period days

      Christine M.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini 3-Pack
      Was this helpful?
    • Rated 1 out of 5 stars
      2 days ago
      Not leakproof at all

      These do not work. Leaked within the first few hours. I saw all the negative reviews and should have not made the purchase. And to ask for a refund, they want me to jump thru hoops first. I am unhappy with the product and instead I have to do all these other actions first. I’m not impressed with this product and such a shame because I liked the idea of using these.

      Jennifer D.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini
      Was this helpful?
    • Rated 1 out of 5 stars
      4 days ago
      Not actually leakproof

      I got these in an effort to switch from tampons and pads even when at work, and the extra absorbency in these ones supposedly absorbs multiple tampons worth of blood. That is not the case. I bled around and then through these underwear and then my pants at work. Disappointing.

      Mallory C.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini
      Was this helpful?
    • Rated 5 out of 5 stars
      2 weeks ago
      Highly recommend

      Was skeptical about buying period underwear and fully getting rid of tampons, but I’m so glad I decided to try it. These underwear are great and holds very well. My flow is heavy the first two days and I didn’t have any problems. Highly recommend if you’re questioning!

      Macayla B.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini
      Was this helpful?
    • Rated 5 out of 5 stars
      2 weeks ago
      5 Stars

      Love them! Very absorbing.

      Maricela
      Reviewing
      Super Leakproof® No-Show Bikini
      Was this helpful?
    • Rated 5 out of 5 stars
      2 weeks ago
      5 Stars

      These are amazing

      Maricela
      Reviewing
      Super Leakproof® No-Show Bikini
      Was this helpful?
    • Rated 4 out of 5 stars
      3 weeks ago
      It doesnt have quite as much coverage as I would like

      Its ok, but not as broad in the butt as i would like - they shift a lot

      Emilie A.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini
      Was this helpful?
    • Rated 5 out of 5 stars
      4 weeks ago
      Love these

      So comfortable!

      Lily G.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini
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    • Rated 5 out of 5 stars
      1 month ago
      Love the additional capacity...

      Like the regular leakproof but with more capacity for longer days or more strenuous activities.

      Rebecca C.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini
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    • Rated 4 out of 5 stars
      1 month ago
      Me

      I feel more confident in my daily routine.

      Rose T.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini
      Was this helpful?
    • Rated 2 out of 5 stars
      1 month ago
      Leak proof underwear

      The new design is awful they do not fit correctly anymore my recommendation would be to go back to the old design!

      Bridgette G.
      Verified Buyer
      Reviewing
      Super Leakproof® No-Show Bikini
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