Your Bag

Your cart is empty

But you're full of potential..
Rewards Members Earn 0 Points

Suggestions

Top Picks

Super Leakproof® Dream Short

$48.00 USD

Color: Tapestry Limited Edition

Revolution V-Neck Bra

$65.00 USD
10% off Bra & Underwear Sets*

Color: Warm Sand

FreeFlex™ Demi Bra

$68.00 USD
10% off Bra & Underwear Sets*

Color: Black

Home / Boyshort Underwear / SuperPlus Leakproof® No-Show Boybrief
New

SuperPlus Leakproof® No-Show Boybrief

$39.00 USD

Mix & Match: 3+ for $33 each
Checkmark

Absorbs 7-11 super tampons

Checkmark

Front-to-back liner

Checkmark

Bonded seams prevent leaks

Checkmark

Machine washable

Ashley has 39” hips and wears KNIX S | Black

Ashley has 39” hips and wears KNIX S

| Black
Ashley has 39” hips and wears KNIX S | Black

Ashley has 39” hips and wears KNIX S

Ashley has 39” hips and wears KNIX S | Black

Ashley has 39” hips and wears KNIX S

| General

Ashley has 39” hips and wears KNIX S

Absorbency: Ultra

Ultra
Drop
Drop
Drop
Drop
Drop
about 7-11 super tampons
Moderate
Drop
Drop
Drop
Drop
Drop
about 2-4 super tampons

Color: Black

Size:

True to Size

•

Size:

Size and Fit Guide

Free Shipping on orders $100+

Shipping

Shipping
Processing Time

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.

Delivery Time

For the most up-to-date delivery time estimates, please refer to the shipping timeline at checkout. Delivery timelines vary depending on location and do not include processing times.

Shipping Charges

Orders over $100* USD = Free standard Shipping (4-8 business days)**
Expedited = $4.99 USD (3-6 business days)**

Orders under $100* USD = $7.99 USD Standard Shipping (4-8 days)**
Expedited = $9.99 USD (3-6 business days)**

*After discounts, before shipping and taxes. Processing times not included in estimates.
**Military Addresses Excluded. Standard Military Address Shipping = $10.00 USD (est. varies per location)
Easy Exchanges within 30 Days

Returns

Returns

Free Returns

Knix covers the return shipping fees for exchanges and refunds initiated through our Return & Exchange Portal. Exchange orders initiated through our Return & Exchange portal are also eligible for free shipping within the USA and Canada. Please note, the shipping fees on your original order are non-refundable.

Return Policy

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

Sale & Last Call

Items discounted below 30% are eligible for size exchange or store credit. Items discounted 30% and above are final sale – no refunds, store credits, or exchanges can be accommodated.
Rewards Members Earn 39 Points

Comfort-First Fit

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

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

Ashley has 39” hips and wears KNIX S | Black
| Black
Ashley has 39” hips and wears KNIX S | Black
Ashley has 39” hips and wears KNIX S | Black
| General

How to Choose?

Essential

Drop
Drop
Drop
Drop
Drop
  • • Everyday Wear
  • • No leakproof protection
  • tsp
    0 tsp

Heavy

Drop
Drop
Drop
Drop
Drop
  • • heavy period days
  • • overnight protection
  • • light bladder leaks
  • 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

Drop
Drop
Drop
Drop
Drop
  • • light period days
  • • sweat
  • • discharge
  • tsp
    about 1-3 tsp
  • pad
    about 1-3 pantyliners
  • tampon
    about 1-3 regular tampons
  • cup
    about 0.5 menstrual cups

Moderate

Drop
Drop
Drop
Drop
Drop
  • • moderate period days
  • • light bladder leaks
  • • sweat
  • 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

Drop
Drop
Drop
Drop
Drop
  • • extra heavy period days
  • • overnight protection
  • • light bladder leaks
  • 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

Soft Top Layer

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

Holiday Top Picks

Shop All Arrow Right

Overnight Favorites Gift Set

From 
$83.00 USD

The Quintessential Sleep Set

$128.00 USD

Color: Ivory Limited Edition

MNTD Cotton Modal Brief 3-Pack

From 
$70.20 USD
$78.00
Save $8

Shimmer Stretch Bra

$55.00 USD
10% off Bra & Underwear Sets*

Color: Black

Leakproof UltraThin No-Show Bikini Shimmer 3-Pack

$75.00 USD

Color: Tapestry/Burnished Gold/Dark Cherry Limited Edition

SculptRib™ Cotton Long Sleeve Top

$58.00 USD

Color: Black

WingWoman Contour Bra

$68.00 USD
10% off Bra & Underwear Sets*

Color: Black

Modal Rib Henley Sleep Set

$68.00 USD

Color: Black

4.5
Rated 4.5 out of 5 stars
Based on 12 reviews
Total 5 star reviews: 9 Total 4 star reviews: 1 Total 3 star reviews: 1 Total 2 star reviews: 1 Total 1 star reviews: 0
83%would recommend this product
Write a Review (Opens in a new window)
12 reviews
  • Rated 5 out of 5 stars
    4 minutes ago
    5 Stars

    Really nice coverage and feel!

    Deborah
    Was this helpful?
  • Rated 5 out of 5 stars
    Yesterday
    5 Stars

    Love these! Haven’t used anything else in years for my cycle.

    Veroniqca
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    SUPER PURCHASE!

    These Boybriefs are great, just the right amount of body coverage, along with the fact they are the top absorbancy.

    Liza S.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    love my no-show boybrief

    i have tried a few different ones. i like them all boy brief the best.

    Judy A.
    Verified Buyer
    Was this helpful?
  • Rated 3 out of 5 stars
    1 week ago
    Good product, not for me

    I really like the extra coverage of this boy brief, but it turns out that extra leakproof is too much for me. I do like the fit. If you need more leakproof then this product would probably be great for you.

    Dee M.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    5 Stars

    Buttery soft. So comfy

    Lisa
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    5 Stars

    Excellent quality. Very comfortable. Buttery soft

    Lisa
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    5 Stars

    Love the fit and feel

    Lisa
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    What I've been waiting for!

    I love Knix's leakproof undies but I always leak in the front overnight because I sleep on my stomach. This is what I've been waiting for! I couldn't wait to try them out so grabbed a pair to try as soon as they launched, and was able to use it right away - works like a charm! Will definitely be switching to these for overnight use on my period from now on!

    Ashley G.
    Verified Buyer
    Was this helpful?
  • Rated 2 out of 5 stars
    2 weeks ago
    Ultra absorbency not absorbent enough for me

    I wanted size XS to work for me, however it wasn't snug enough fit. I am going to try the shorts hoping the fit around thighs will seal in leaks?

    Joanne C.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    2 weeks ago
    My new favorite pair

    So so comfortable and tummy control

    Amber G.
    Verified Buyer
    Was this helpful?
  • Rated 4 out of 5 stars
    2 weeks ago
    Skeptics look!

    I had ordered leakproof undies from the “other company “ I Washed the undies before wearing them. They shrunk two sizes! I was unable to wear them at all. I did not receive a full refund as I washed the products. Then it cost me $28.00 to mail them back!

    I was extremely worried when I ordered the Knix if i would encounter the same problem. The boy shorts arrived quite quickly. I had never wore boy shorts before and was pleased with the comfort and fit. No pinching or sliding down. I wear a 3x. The boy shorts are roomy but not sloppy. Very little show under snugger clothing. All in all i was very pleased with my purchase and they did not shrink in the wash. Although this time i do not put them in the dryer but hang to dry.

    Patricia G.
    Verified Buyer
    Was this helpful?

Save on Underwear Kits

Shop Now Arrow Right

The Full Cycle Kit - High Rise

From 
$141.60 USD
$177.00
Save $35

The Full Cycle Kit - Bikini

From 
$127.20 USD
$159.00
Save $31

Super Leakproof® Dream Team Kit

From 
$96.00 USD

Super Leakproof® Dream Short 3-Pack

From 
$99.00 USD
$144.00
Save $45

24/7 Leakproof Kit - High Rise

From 
$128.00 USD
$160.00
Save $32

24/7 Leakproof Kit - Bikini

From 
$120.00 USD
$150.00
Save $30

The Heavy Flow Kit - Bikini

From 
$140.80 USD
$176.00
Save $32

The Heavy Flow Kit - High Rise

From 
$153.00 USD
$192.00
Save $38