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Super Leakproof® Cotton Boybrief

$36.00 USD

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

Absorbs about 6 super tampons

Breathable cotton

More absorbency without the bulk

Machine washable

| Dusty Pink
| Dusty Pink
| Dusty Pink
| Dusty Pink
| General

Color: Dusty Pink Limited Edition

Size:

True to Size

Size:

Size and Fit Guide

Build Your 3-Pack

Super Leakproof® Cotton Boybrief

Color: Dusty Pink Limited Edition

Size:

Size:

Super Leakproof® Cotton Boybrief

Color: Dusty Pink Limited Edition

Size:

Size:

Super Leakproof® Cotton Boybrief

Color: Dusty Pink 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

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

Comfort-First Fit

A mid-rise boyshort with full bum coverage.

Heavy Absorbency

Absorbs about 6 super tampons worth of liquid—great for heavy days or overnights.

Cozy Cotton-Blend

Soft cotton with a hint of spandex feels luxurious against your skin.

Worry-Free Protection

An innovative floating gusset provides leak protection from every angle.

Easy to Wash

Machine washable just like regular underwear.

Zoom

| Dusty Pink
| Dusty Pink
| Dusty Pink
| Dusty Pink
| 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
FRESH FIX TECHNOLOGY®

Cotton meets patented protection.

A sewn-in, floating liner soaks up about 6 super tampons’ worth of liquid—so you stay fresh, comfortable, and in control.

Soft Top Layer

Gently wicks away moisture to keep you fresh and odor-free.

4.0
Rated 4.0 out of 5 stars
Based on 20 reviews
Total 5 star reviews: 9 Total 4 star reviews: 4 Total 3 star reviews: 5 Total 2 star reviews: 2 Total 1 star reviews: 0
65%would recommend this product
FitRated 0.0 on a scale of minus 2 to 2
ComfortRated 4.0 on a scale of 1 to 5
EffectivenessRated 3.7 on a scale of 1 to 5
Ease of UseRated 4.0 on a scale of 1 to 5
20 reviews
  • Rated 5 out of 5 stars
    5 days ago
    5 Stars

    Love the stretchy fit and full coverage

    Kathleen
  • Rated 5 out of 5 stars
    1 week ago
    Awesome

    Fits perfectly, no tugging, rising up, or sticking, plus has extra leakproof protection!

    LORETTA H.
    Verified Buyer
  • Rated 5 out of 5 stars
    1 week ago
    My fav period underwear!

    These are my favourite of all the period underwear cuts that I have tried. They are very comfortable, stay in place and no leaks. Full bum coverage too, which I like. Easy to clean. Absolutely love these!

    Michelle H.
    Verified Buyer
  • Rated 5 out of 5 stars
    2 weeks ago
    Great choice for cotton!

    Love the soft cotton The waist elastic has been changed from the last time I ordered these. Surprised me when I opened this package.

    Christa H.
    Verified Buyer
  • Rated 5 out of 5 stars
    3 weeks ago
    Cotton

    Very comfortable and fit well. Great leakage protection. I find the cotton more comfortable than the regular panties.

    Leslie J.
    Verified Buyer
  • Rated 5 out of 5 stars
    3 weeks ago
    Super leakproof cotton boybrief

    Good fit

    Susan Z.
    Verified Buyer
  • Rated 5 out of 5 stars
    1 month ago
    5 Stars

    The one I wear tested was the boyshort - for my initial wear the waist and leg opening was comfortable, no pressing at all.

    Sihong Y.
  • Rated 5 out of 5 stars
    1 month ago
    5 Stars

    The boyshort style was very comfortable, fabric breathable and light weight. Great gusset coverage front and back.

    Sihong Y.
  • Rated 5 out of 5 stars
    1 month ago
    5 Stars

    The fabric is so soft and comfy! I love how it is stretchy and relaxed right away. I am someone who has thicker thighs and so sitting down for long periods of time wearing the BeyondSmooth fabric underwear is uncomfy for me because it digs in. I didn't feel that way with this style. When I'm on my period, I want to feel as comfy as possible so I really appreciated the true to size leg and waist openings on this style. I also loved the length on the front, it feels like a mid-rise on me which is how I would expect this style to sit.

    Sarah P.
  • Rated 4 out of 5 stars
    1 week ago
    Love the NEW updated 2026 panties!

    I have been trying to get a return email on the previous edition of these panties. I have 5 pair from first edition 2025 that are no good and have been trying to return since a month after purchase. The pad ripped immediately.

    However THESE specific current edition is a much improved style with the pad is multiple stitches unlike first edition. so far. Please contact me for exchange for new ones as I have requested now multiple times!

    Michelle A.
    Verified Buyer
  • Rated 4 out of 5 stars
    3 weeks ago
    Like these boybriefs!

    It took a bit to get use to the feel if the back of the panty. Once I did I really liked them.

    Nancy M.
    Verified Buyer
  • Rated 4 out of 5 stars
    1 month ago
    Nice but not perfect

    Feel a little bulky but still nice

    Judith C.
    Verified Buyer

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