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Home / Boyshort Underwear / Leakproof UltraThin No-Show Boybrief

Leakproof UltraThin No-Show Boybrief

$34.00 USD

Mix & Match: 3+ for $25 each
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Absorbs about 2.5 super tampons

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Invisible under clothes

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Moderate protection without the bulk

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Machine washable

| Black
| Black
| Black
| Black

Absorbency: Moderate

Moderate
Drop
Drop
Drop
Drop
Drop
about 2-4 super tampons
Ultra
Drop
Drop
Drop
Drop
Drop
about 7-11 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 34 Points

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

Made from our signature buttery soft fabric with a wide, comfortable waistband. Wear it on its own or under your favorite pajamas.

Easy to Wash

Machine washable just like regular underwear.

Zoom

| Black
| Black
| Black
| Black

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
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

Soft Top Layer

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

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4.7
Rated 4.7 out of 5 stars
Based on 50 reviews
Total 5 star reviews: 41 Total 4 star reviews: 4 Total 3 star reviews: 3 Total 2 star reviews: 2 Total 1 star reviews: 0
90%would recommend this product
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50 reviews
  • Rated 5 out of 5 stars
    4 minutes ago
    5 Stars

    Amazing

    Ive been wearing knix regular brief but absolutely love these so stocking up. Im runnng out of lingerie drawer space! Please make mire colors

    Carole
    Was this helpful?
  • Rated 5 out of 5 stars
    2 days ago
    Great undies, fit really well

    I ordered three pairs of the Leakproof Boy Briefs andI really like them. They fit well and are very comfortable.

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

    Love them this the fourth order

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

    Amazing products

    Shelby
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    Boybriefs are fantastic

    Just love my new buried underwear, they are my new favourites.

    Dolores K.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    Leakproof Ultra Thin No-Show Boy Brief

    These briefs are exactly as described. They are so comfortable and it’s like not wearing anything. The leakproof liner does a great job of containing any fluid. The material is very soft on the skin.

    Theses panties wash well and keep their shape too!

    Catherine D.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    2 weeks ago
    Love them

    Very comfortable

    SHARON B.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    2 weeks ago
    So very comfortable!

    I love these briefs. No lines, smooth and of course, comfortable. The liners absorb really well and are comfortable.

    I truly recommend these boybriefs.

    Laurie K.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    2 weeks ago
    Amazing

    Im so happy with these!! Its been so nice to get rid of those pads and panty liners. Ive been amazed at how good and confident I feel!!

    Kellie V.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    2 weeks ago
    Chic comfort

    I am so glad that I tried the boyfriend

    Must have 20 pair of regular briefs and while I like them very much, I LOVE the boyfriend

    Have to start adding more boyfriends to the collection

    I love Knix

    Carole C.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    3 weeks ago
    No-show Boybrief

    The no-show Boybrief is everything it claims to be, discreet, effective and comfortable.

    Greta H.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    3 weeks ago
    Good coverage

    Really like the secure fit

    Vicky C.
    Verified Buyer
    Was this helpful?