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Home / Boyshort Underwear / Leakproof UltraThin No-Show Boybrief

Leakproof UltraThin No-Show Boybrief

$34.00 CAD

Mix & Match: 3+ for $25 each
Checkmark

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

Leakproof Underwear is Sales Tax Free in Canada*
Get FREE Express Shipping on all orders $125+

Shipping

HOLIDAY SHIPPING

Give the gift of Knix! To receive your order by Dec 24th, please order by the following dates.

Toronto, Ottawa, Montreal, Winnipeg, Regina, Calgary, Edmonton, Vancouver
Standard & Expedited: Monday, December 22

Urban Centres (excluding the above)
Standard: Wednesday, December 17
Express: Sunday, December 21

Rest of Canada
Standard: Sun, December 14*
Express: Thu, December 18*
*YK, NWT, NT, NL, and remote areas across Canada.

For locations serviced solely by Canada Post, please allow at least 5 additional days due to rotating strikes. This applies to P.O Box and RR addresses.

To avoid any additional delays during the rotating strikes, we will use alternate carriers when possible.

Please note: Weather conditions and carrier issues may cause delays. Delivery dates are not guaranteed.

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.

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* CAD = Free Shipping (2-6 business days)
Orders under $100* CAD = $12 CAD Shipping (1-3 business days)
Orders delivering to NWT, Nunavut and Yukon are subject to $20 delivery fee.
*After discounts, before shipping and taxes.
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.
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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
| 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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4.8
Rated 4.8 out of 5 stars
Based on 58 reviews
Total 5 star reviews: 52 Total 4 star reviews: 3 Total 3 star reviews: 3 Total 2 star reviews: 0 Total 1 star reviews: 0
95%would recommend this product
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58 reviews
  • Rated 5 out of 5 stars
    4 minutes ago
    Love the boybrief!

    I am so happy to have this new cut! My bum is rather flat so I hadn't received the coverage I desired until these (although I tried to make the briefs work). Thanks for making a style that offers better coverage for those of us who no longer strive to be flirty - as I complete my sixth decade on earth.

    HEIDI K.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    13 hours ago
    Comfy fit and does the trick!

    These are so comfy and I love how they fit. Not your traditional period panty.

    Morganne S.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    Yesterday
    5 Stars

    Great

    Carol
    Was this helpful?
  • Rated 5 out of 5 stars
    2 days ago
    No Show Boy-brief

    ⭐⭐⭐⭐⭐

    Bronwen W.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    2 days ago
    Worry proof comfort

    Being a senior lady, I needed something comfortable & reliable for leaks. These are amazing & fit the requirements. So glad I found knix!

    Susan G.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    3 days ago
    Best Fit

    I love how Boybriefs fit. They've been my favorite for several years and the Leakproof Ultra Thin No-Show is a real plus for comfort and confidence. Thanks KNIX.

    Ann L.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    3 days ago
    Best undies!

    Excellent fit

    Comfortable

    Wears well

    Sandra C.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    4 days ago
    Love these

    No panty lines changes the game on what I can wear that time of the month. Such a life saver!

    Rachel E.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    6 days ago
    My favorite fit

    Love these they are so comfortable.

    Susan W.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    6 days ago
    Keep ordering

    Love thaws so much rhat I keep ordering

    Tamara L.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    My purchases feedback

    I couldn’t be happier with my purchases! What a treat to wear the bras and the panties that are SO comfortable!! Thrilled that they dry overnight after laundering!! Thank you!!

    Jennifer S.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    1 week ago
    My new go-to panties.

    Very comfortable! They fit perfectly and there are no panty lines - even under my workout leggings.

    Michelle C.
    Verified Buyer
    Was this helpful?