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Leakproof UltraThin No-Show Boybrief

$34.00 USD

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

Absorbs about 2.5 super tampons

Invisible under clothes

Moderate protection without the bulk

Machine washable

| Black with White Polka Dot
| Black with White Polka Dot
| Black with White Polka Dot
| Black with White Polka Dot

Color: Black with White Polka Dot Limited Edition

Size:

True to Size

Size:

Size and Fit Guide

Build Your 3-Pack

Leakproof UltraThin No-Show Boybrief

Color: Black with White Polka Dot Limited Edition

Size:

Size:

Leakproof UltraThin No-Show Boybrief

Color: Black with White Polka Dot Limited Edition

Size:

Size:

Leakproof UltraThin No-Show Boybrief

Color: Black with White Polka Dot Limited Edition

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

Leakproof Underwear, Risk Free
Trying leakproof underwear for the first time? Your first pair is completely risk free for 30 days. Wear them, wash them, and see how they work for your body. If they’re not right for you, we’ll refund your first pair. Prefer a different size or style? We also offer free exchanges.

How it works:

  • Risk free applies to leakproof underwear on your first order
  • Refund covers the item price (original shipping excluded)
  • Just email info@knix.com and we’ll take care of you

Return Policy
Return policy varies by product, please check if your item is refund or exchange eligible by viewing our full policy here.

Rewards Members Earn 34 Points

Product Description

These underwear feature our buttery soft fabric and offer full coverage for the hips and bum. Great for leak protection, the ultra-thin liner absorbs about the same as 2.5 super tampons or 1 regular pad’s worth. Get the protection you want from periods and light bladder leaks while feeling comfortable and worry-free.

Comfort-First Fit

Mid-rise boybrief silhouette with full bum coverage for a smooth, comfortable fit.

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 regular underwear.

Zoom

| Black with White Polka Dot
| Black with White Polka Dot
| Black with White Polka Dot
| Black with White Polka Dot

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.

4.7
Rated 4.7 out of 5 stars
Based on 149 reviews
Total 5 star reviews: 124 Total 4 star reviews: 10 Total 3 star reviews: 7 Total 2 star reviews: 6 Total 1 star reviews: 2
90%would recommend this product
149 reviews
  • Rated 5 out of 5 stars
    3 minutes ago
    Love it!

    I just love this style! So comfortable! The fit is perfect. I will buy more! Please add more colours!

    Nathalie L.
    Verified Buyer
  • Rated 5 out of 5 stars
    23 hours ago
    No show brief

    Comfortable

    Dorothy C. K.
    Verified Buyer
  • Rated 5 out of 5 stars
    23 hours ago
    Home with baby

    I purchased the Knox underwear and nursing bras for my daughter in law post birth. She loves the knix wear. She said it is comfortable and stylish.

    Mary D.
    Verified Buyer
  • Rated 5 out of 5 stars
    23 hours ago
    My new favourite!

    I got these along with a few other new styles to try and wish I had just got multiple of these. They are so comfortable, really lightweight and not bulky given the flow levels, and unlike the boy short style absolutely no riding up. Please make them in more colours, and in the lighter flow level!

    Hils
    Verified Buyer
  • Rated 5 out of 5 stars
    Yesterday
    Boybrief

    Obsessed with these boybrief undies, I’ve it in all colours!!! Love it!! Pls have it in more colours!!!

    Maria
    Verified Buyer
  • Rated 5 out of 5 stars
    3 days ago
    Very comfortable

    Boys undies

    Linda D.
    Verified Buyer
  • Rated 5 out of 5 stars
    1 week ago
    ultra thin no show boybrief

    super comfortable!! i wish i had ordered 3 pair if these instead of french cut.

    LUANN B.
    Verified Buyer
  • Rated 5 out of 5 stars
    1 week ago
    Perfect fit

    Perfect fit and so comfortable

    Kim W.
    Verified Buyer
  • Rated 5 out of 5 stars
    1 week ago
    5 Stars

    Great love the fit

    Jacqueline
  • Rated 5 out of 5 stars
    2 weeks ago
    Leakproof UltraThin No-Show Boybrief

    Meets all expectations. Very comfortable.

    Pamela L.
    Verified Buyer
  • Rated 5 out of 5 stars
    3 weeks ago
    Rave review

    These are the best things I've ever seen! I feel confident and secure. Thank for inventing such a wonderful product!

    Cecilia M. C.
    Verified Buyer
  • Rated 5 out of 5 stars
    3 weeks ago
    Boy briefs

    I quite like these briefs.. as a senior/senior I feel well protected wearing them in fact I have Knix briefs in every style and color and wear nothing else. I also have tee shirts, joggers and nightgowns!!! The joggers are incredible fabric, too long and big for me but I gave them to my granddaughter who also is a Knix customer and she loves them! In fact we are 3 generations KNIX customers!!!

    Linda J.
    Verified Buyer

Your underwear questions, answered.