Super Leakproof® No-Show Underwear Boyshort

With the ability to hold about 3 super tampons’ or 1.5 regular pads' worth of blood, this super-absorbent boyshort underwear works just as hard as you do—no backup needed. With our patented leakproof technology and quick-drying fabric, they’re a game-changer for training and recharging with protection against sweat, discharge, and blood, on heavy days or nights.

Key Features:

- Quick-Drying

- Moisture and Sweat Wicking

- Absorbs the same as about 3 super tampons or 1.5 regular pads

- Super soft & stretchy

- Invisible under leggings or shorts (aka no visible seam lines)

- Patented leakproof technology

school. sofa. sleep. you’ll wear these period undies everywhere.
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Holds the same as about 3 super tampons
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Rapidly absorbs moisture to keep you fresh and dry all day.
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Allows air to circulate to keep you cool and dry.
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Simply care with mild detergent and machine wash on cold.

With the ability to hold about 3 super tampons’ or 1.5 regular pads' worth of blood, this super-absorbent boyshort underwear works just as hard as you do—no backup needed. With our patented leakproof technology and quick-drying fabric, they’re a game-changer for training and recharging with protection against sweat, discharge, and blood, on heavy days or nights.

Key Features:

- Quick-Drying

- Moisture and Sweat Wicking

- Absorbs the same as about 3 super tampons or 1.5 regular pads

- Super soft & stretchy

- Invisible under leggings or shorts (aka no visible seam lines)

- Patented leakproof technology

Machine wash cold with mild detergent, do not bleach, lay flat to dry.


Body: 70% Nylon, 30% Spandex 

Lining: 84% Modal, 8% Seaweed, 8% Spandex 

Gusset: Fresh Fix Technology®, 100% Polyester, PU Film

 

Additional Product Ingredient Information

For items with a 20% or more discount, you may exchange for another item or return for store credit. No refunds can be accommodated. 

Items marked as “Flash Sale” or “Clearance” are final sale, meaning no returns, exchanges or refunds can be accommodated. No exceptions. 

Please note: Sale items are not eligible for our First Pair Risk-Free Policy.


We offer free standard shipping on all orders over $70. 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.

US Orders: Please allow 3–10 business days for orders to arrive. 

International Orders: Please allow 10–25 business days for orders to arrive.  

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

CANADIAN CUSTOMERS: Shop www.knixteen.ca to order in Canadian currency.

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nothing is tmi here—we promise.
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Heavy Absorbency

Absorbs about the same as 3 super tampons. Perfect for overnight protection or your teens heaviest days when changing into a fresh pair might not be convenient.


Medium Absorbency

Absorbs about 2.5 super tampons' worth of blood. Ideal for medium period days, discharge and sweat.


Lightest Absorbency

Absorbs about the same as about 1 regular tampon worth of blood, sweat or discharge. Ideal for lightest period days, spotting, sweat and discharge.

Each pair has a built-in liner that absorbs period blood. Kt Period Underwear is categorized by lightest, medium and heavy flows so you can find the right pair for your teen’s needs.

All of our period underwear, swimwear, reusable pads, and activewear have our patented leakproof technology built right in. Liner’s are discreet and comfortable, and fit for your teen’s unique flow. 

That’s up to your teen or tween! Every flow and comfort level is different.

Depending on the absorbency level of the period underwear and the heaviness of your teen’s flow, they can wear our period undies on their own or as a backup to tampons or menstrual cups. 

We always recommend they choose an option that makes them feel most confident!

Step 1: Give your teens underwear a quick rinse under cold water.

Step 2: Throw it in the washing machine with your regular clothes. Wash on cold with mild detergent (no softener or bleach).

Step 3: There are two ways to dry them depending on the undies you have: lay flat to dry for medium absorbency products, or tumble dry on low for high to super absorbency products.

Step 4: That’s it! No ironing needed.

Check out our size chart here. If you want some help, we have virtual fitters ready on deck to help your teen find their perfect fit. Book a video call with them today.

Because they’re, well, underwear, we can’t accept exchanges or returns on used items. BUT your teen can try their first pair on your first order risk-free for 30 days!

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 order included multiple period underwear, open, wash, and wear one pair only. That way if you don’t love them, any unopened packages from the same purchase will be 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.

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Sustainable
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Absorbent
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Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Image of a chrome heart surrounding text
Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Image of a chrome heart surrounding text
Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Image of a chrome heart surrounding text
Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Image of a chrome heart surrounding text
Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Image of a chrome heart surrounding text
Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Image of a chrome heart surrounding text
Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Image of a chrome heart surrounding text
Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Image of a chrome heart surrounding text
Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Image of a chrome heart surrounding text
Comfortable
Image of a chrome heart surrounding text
Sustainable
Image of a chrome heart surrounding text
Absorbent
Reviews
average rating 4.7 out of 5
Based on 443 reviews
  • 5 Stars
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95% of reviewers would recommend this product to a friend
Write a Review
Review posted
Reviewed by Kelly T.
Verified Buyer
Super Leakproof® No-Show Underwear Boyshort
Reviewing
Super Leakproof® No-Show Underwear Boyshort
I'm a...
Parental Figure
I purchased for...
A Teenager/Tween
Pant Size
Kids 12-14
Size Purchased
XS
Usage
  • Primary Protection
Rated 5 out of 5

An essential for young girls

My daughter absolutely loves these. She has felt comfortable and confident during her first few cycles.

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I recommend this product
Quality
Rated 5 out of 5
Comfort
Rated 5 out of 5
Sizing
Rated 0 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 5 out of 5
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Review posted
Reviewed by Mary T.
Verified Buyer
Super Leakproof® No-Show Underwear Boyshort
Reviewing
Super Leakproof® No-Show Underwear Boyshort
I'm a...
Parental Figure
I purchased for...
A Teenager/Tween
Pant Size
Teen 00-2
Size Purchased
S
Usage
  • Back-up Protection
  • Period
  • Primary Protection
Rated 5 out of 5

So far so good!

My 14 year old daughter just got a few pairs to try and she finds them really comfortable. She wants me to get a few more pairs for her light days. We used the size guide and thought she was a small but are thinking she is an extra small..she has a really tiny bum and skinny legs.

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Quality
Rated 5 out of 5
Comfort
Rated 5 out of 5
Sizing
Rated 1 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 4 out of 5
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Reviewed by Janna S.
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Super Leakproof® No-Show Underwear Boyshort
Reviewing
Super Leakproof® No-Show Underwear Boyshort
Rated 5 out of 5

leakproof swim shorts

My granddaughter loves her leakproof swim shorts and was able to put them to good use recently. It meant she didn't have to miss any of her swimming lessons.

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Reviewed by Christine P.
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Super Leakproof® No-Show Underwear Boyshort
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Super Leakproof® No-Show Underwear Boyshort
Rated 5 out of 5

Love!

Even though I am WAY past my teen years, this is my favourite style of Knix. Love the teen boy short style and find they fit slightly smaller than the adult version of comparable size. Exactly what I want.

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Reviewed by Jessica H.
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Super Leakproof® No-Show Underwear Boyshort
Reviewing
Super Leakproof® No-Show Underwear Boyshort
I'm a...
Adult
I purchased for...
Myself
Pant Size
Teen 4-10
Size Purchased
M
Usage
  • Back-up Protection
Rated 5 out of 5

Love

I didn’t think I would like these as much as I do! My new go to period undies.

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Quality
Rated 5 out of 5
Comfort
Rated 5 out of 5
Sizing
Rated 0 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 5 out of 5
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