Cotton Modal Super Leakproof Boxer Brief - Last Call

Ultra-soft cotton boxer brief featuring extra leg length and our longest super leakproof gusset ever. Absorbs up to 10 tampons or pads worth of blood.

the most requested underwear in our lineup.
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Holds up to 10 tampons or pads worth of blood.
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Rapidly absorbs moisture to keep you fresh and dry all day.
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Simply care with mild detergent and machine wash on cold.
Designed with a longer gusset for front-to-back coverage.

Ultra-soft cotton boxer brief featuring extra leg length and our longest super leakproof gusset ever. Absorbs up to 10 tampons or pads worth of blood.

Because they’re, well, underwear, we can’t accept exchanges or returns on used items. BUT you can try your first pair on your first order risk-free for 30 days! Learn more about our First Pair Risk-Free Policy.

We offer free standard shipping on all orders over $80.

We ship our items via DHL or Canada Post depending on your location. Please allow 1-2 business days for your items to be processed and shipped. During high volume periods, your order may take up to 7 business days to dispatch from our warehouse location. 


Canadian Orders: Please allow 2–4 business days for shipping to the GTA, 3–10 business days for urban areas, and 6–15 business days for remote locations.


NOTE: Orders placed on Friday after 1 PM will not be processed until the following Monday.

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FOR THE PLANET
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KT by Knix Period Underwear FAQs

Super Absorbency
A total replacement for disposable period products - absorbs approximately 8 tsp, 40 ml, or the equivalent of 8 regular tampons worth of liquid.

High Absorbency
Ready to stop leaks whenever - absorbs approximately 4-6 tsp, 20-30 ml, or the equivalent of 4-6 tampons worth of liquid. 

Medium Absorbency
Confident backup protection for heaviest days - absorbs approximately 3 tsp, 15 ml, or the equivalent of 2 tampons worth of liquid.

We have a First Pair Risk-Free Return Policy for your first order - no ifs ands or buts! So if you ordered the wrong size of Period Underwear, we’ll send you a different pair at no cost or offer you a standard refund within 30 days of delivery (excluding original shipping fees).

If your first order included multiple Period Underwear: OPEN, WASH & WEAR ONE PAIR ONLY to be sure you love them. That way if you don’t, any unopened packages from the same purchase are also eligible for an exchange or standard refund (excluding original shipping fees).

All unopened packages will be donated to local organizations to support people in need.

Our Period Underwear features triple layer technology that ensures you stay fresh, dry, and protected. The anti-odor top layer wicks away moisture from your skin; the inner-layer absorbs the liquid and locks it in; and the leak resistant outer layer keeps any liquid from spotting your clothes.

Washing your period underwear shouldn't be complicated, so we designed our products to be super easy to wash and care for. For best results, machine wash on cold with mild detergent and tumble dry on low (Super Leakproof Underwear). That's it! Pro tips: Don't use softener or bleach and never iron.

Depending on the level of absorbency of leakproof period underwear you choose and the heaviness of your flow, you can wear our period panties on their own or as backup protection along with a pad or tampon. You're totally protected with our high and super absorbency leakproof underwear, while our low and medium absorbency leakproof underwear can replace pads and tampons on lighter days and work great as a backup for your usual period protection on heavier days.

If you want help finding the perfect Period Underwear product size for you, connect with one of our expert Knix team members for a 1-on-1 fitting session over video chat. Book a time that’s convenient for you, and we’ll walk you through everything! 

Book Now

COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
Reviews
average rating 3.3 out of 5
Based on 3 reviews
  • 5 Stars
    1 Review
  • 4 Stars
    1 Review
  • 3 Stars
    0 Reviews
  • 2 Stars
    0 Reviews
  • 1 Star
    1 Review
67% of reviewers would recommend this product to a friend
Review posted
Reviewed by Amy S.
Verified Buyer
Rated 5 out of 5

Great overnight briefs

Comfortable and great coverage!

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Fit
Rated 0 on a scale of minus 2 to 2, where minus 2 is Runs Small, 0 is True to Size and 2 is Runs Large
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Review posted
Reviewed by Felicia S.
Verified Buyer
Rated 4 out of 5

Feel safe and secure at night

I really like these for sleeping. The long pad plus the short style cut makes me feel secure and unafraid of leaks. I do find that the high rise of the waist sits a bit too high on my torso. Not a big deal but feels a bit odd at times.

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Review posted
Reviewed by Jessah D.
Verified Buyer
I'm a...
Adult
I purchased for...
Myself
Pant Size
Teen 12-16
Size Purchased
M
Usage
  • Primary Protection
  • Period
Rated 1 out of 5

Waist band issue

Waist band too tight (not similar to other mediums purchased). Cannot wear at all.

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I don't recommend this product
Quality
Rated 4 out of 5
Comfort
Rated 1 out of 5
Sizing
Rated -2 on a scale of minus 2 to 2, where minus 2 is Fits Small, 0 is True to SIze and 2 is Fits Large
Effectiveness
Rated 2 out of 5
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