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Home / Thong Underwear / Light Leakproof UltraThin No-Show Thong
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Light Leakproof UltraThin No-Show Thong

$18.90 USD

$27.00

20-30% off

Absorbs about 2 regular tampons

Invisible under clothes

More absorbency without bulk

Machine washable

Isabelle has 40” hips and wears a Knix size M | Sola

Isabelle has 40” hips and wears a Knix size M

Isabelle has 40” hips and wears a Knix size M | Sola

Isabelle has 40” hips and wears a Knix size M

Isabelle has 40” hips and wears a Knix size M | Sola

Isabelle has 40” hips and wears a Knix size M

| General
| General
| General
| General

Isabelle has 40” hips and wears a Knix size M

Absorbency: Light

Light
about 1-3 regular tampons
Essential
No Absorbency
Moderate
about 2-4 super tampons

Color: Sola

Size:

True to Size

•

Size:

Size and Fit Guide

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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 18 Points

Product Description

Made with our signature buttery soft fabric, this leakproof thong has absorbency without the bulk. Great for leak protection, the ultra-thin liner absorbs about the same as 2 regular tampons or 2 pantyliners worth. Our patented 360 LeakSeal™ technology locks in leaks at every edge.

Comfort-First Fit

Thong silhouette sits lower on the hip with minimal 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

It absorbs about 2 regular tampons worth of liquid—great for regular flow days, light bladder leaks, and sweat.

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

Isabelle has 40” hips and wears a Knix size M | Sola
Isabelle has 40” hips and wears a Knix size M | Sola
Isabelle has 40” hips and wears a Knix size M | Sola
| General
| General
| General
| 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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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.

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.

    4.0
    Rated 4.0 out of 5 stars
    Based on 255 reviews
    Total 5 star reviews: 161 Total 4 star reviews: 22 Total 3 star reviews: 20 Total 2 star reviews: 15 Total 1 star reviews: 37
    74%would recommend these products
    FitRated -0.2 on a scale of minus 2 to 2
    ComfortRated 3.9 on a scale of 1 to 5
    EffectivenessRated 4.1 on a scale of 1 to 5
    Write a Review (Opens in a new window)
    255 reviews
    • Rated 5 out of 5 stars
      3 minutes ago
      These are great!

      Very comfortable and good moisture control for sweat, leaks and period back up.

      Rochelle B.
      Verified Buyer
      Was this helpful?
    • Rated 5 out of 5 stars
      6 days ago
      5 Stars

      I love the many options for your needs and how comfortable everything is.

      Brenda
      Was this helpful?
    • Rated 5 out of 5 stars
      2 weeks ago
      A must have!

      The rise is great for lower rise pants. They fit like a second skin and stay in place all day. They wash up great, and are quick to air dry. These and the high rise version are the only underwear I wear now!

      Jessica A.
      Verified Buyer
      Was this helpful?
    • Rated 5 out of 5 stars
      2 weeks ago
      Thong

      I didn’t think you could get much leakage coverage from a thong but I think they did the best they could with it. It’s more than I thought it could be. Glad I gave them a try.

      MD
      Verified Buyer
      Was this helpful?
    • Rated 5 out of 5 stars
      1 month ago
      LOVE THESE

      Wow, these are a gift made from women, for women! No leaks, used on my day 3-5 of my period with no additional products. LOVE!

      Sara R.
      Verified Buyer
      Was this helpful?
    • Rated 5 out of 5 stars
      1 month ago
      5 Stars

      Very comfy and not frumpy like others.

      Jacki
      Was this helpful?
    • Rated 5 out of 5 stars
      2 months ago
      Repeat Customer

      Works well!

      Kaitlyn E.
      Verified Buyer
      Was this helpful?
    • Rated 5 out of 5 stars
      2 months ago
      Soo comfy

      These are way comfier than the super protection they arent as tight and cause less chafing.

      Morgan S.
      Verified Buyer
      Was this helpful?
    • Rated 5 out of 5 stars
      2 months ago
      No-Show, No-Stress, No-Regrets

      Who knew a thong could be this impressive?

      The Light Leakproof UltraThin No-Show Thong is ridiculously comfortable — soft, smooth, and truly invisible under clothes. No digging, no shifting, no drama.

      The fabric feels amazing (zero irritation), and somehow it still manages to be protective without feeling bulky. The leak protection is discreet but reliable — which means peace of mind without sacrificing cute.

      And can we talk about laundry? It washes beautifully and holds its shape like a champ. No stretching out, no weird warping — just consistent comfort.

      Basically: sleek, secure, and secretly hardworking. 10/10 would buy again.

      Jody G.
      Verified Buyer
      Was this helpful?
    • Rated 5 out of 5 stars
      2 months ago
      Pretty and comfy!

      I was surprised by how much I loved these! I had to order several more!

      Linda B.
      Verified Buyer
      Was this helpful?
    • Rated 5 out of 5 stars
      2 months ago
      Thongs

      I love the fit of the thongs and also the assurance of no leakage!

      Carol D.
      Verified Buyer
      Was this helpful?
    • Rated 5 out of 5 stars
      2 months ago
      Comfortable

      I was told to size down because they stretch out a bit, so I got the small instead of medium. Comfortable and no leakage when wearing them without any other period product as back up

      Jenn P.
      Verified Buyer
      Was this helpful?

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