Super Sleepover Short

Our most absorbent nighttime underwear features a longer gusset (designed to fight period stains and leaks while you snooze!) and an ultra-comfy, bum-covering style. Made with our patented, 3-layer leakproof technology built in.

First layer: Moisture-wicking, antimicrobial technology wicks away sweat and moisture while neutralizing odors to keep you fresh all day long. 

Second layer: A super thin, highly-absorbent liner that holds the power of 12 tampons or pads.

Third layer: A secure, liquid-resistant outer layer keeps leaks from happening. 

Meet the most absorbent nighttime period underwear ever.
Image of a chrome heart surrounding text
Image of a absorbancy surrounding text
Holds up to 12 tampons or pads worth of blood.
Image of a moisture fabric surrounding text
Rapidly absorbs moisture to keep you fresh and dry all day.
Antimicrobial layer kills bacteria and neutralizes smells.
Image of a overnight protection surrounding text
Designed with a longer gusset to prevent leaks all night long.

Our most absorbent nighttime underwear features a longer gusset (designed to fight period stains and leaks while you snooze!) and an ultra-comfy, bum-covering style. Made with our patented, 3-layer leakproof technology built in.

First layer: Moisture-wicking, antimicrobial technology wicks away sweat and moisture while neutralizing odors to keep you fresh all day long. 

Second layer: A super thin, highly-absorbent liner that holds the power of 12 tampons or pads.

Third layer: A secure, liquid-resistant outer layer keeps leaks from happening. 

Body: 70% Nylon, 30% LYCRA® 

Gusset Top Layer: 84% Modal, 8% Seaweed Fiber, 8% Spandex 

Gusset 2nd Layer: 100% Polyester 

Gusset 3rd Layer: LeakProof Technology™

Free from PFAS and other chemical treatments. 

Machine wash cold with mild detergent. Do not bleach. Lay flat to dry.

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!  

What's First-Pair Risk-Free?  

If your first order includes multiple period underwear: OPEN, WASH & WEAR ONE PAIR ONLY to test them out. That way, in the unlikely event that you don’t love them, any unopened packages from the same purchase can be exchanged or refunded back to you within 30 days of delivery (excluding original shipping fees).  All unopened packages will be donated to local organizations to support people in need.

We ship our items via DHL, or Canada Post depending on your location. Please allow 1-2 business days for your order to dispatch.  

For orders to the US please allow 3-10 business days for orders to arrive. For international orders please allow 10-25 business days.  

Please 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 Dollars!

Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
for the planet!
Image of a chrome heart surrounding text
FOR THIS GENERATION
nothing is tmi here—we promise.
Image of a chrome star surrounding text

Super Absorbency

Absorbs up to 12 tsp (60 ml) of blood—that’s about 12 regular tampons or pads! Perfect for overnight protection or on your heaviest days when changing into a fresh pair might not be convenient.

High Absorbency

Absorbs up to 4-8 tsp (20-40 ml) of blood or the equivalent of 4-8 tampons or pads. These are perfect for heavy flow days.

 Medium Absorbency

These absorb approximately 3 tsp (15 ml) or about 3 tampons or pads worth of blood! Ideal for light to medium flow days or as backup to tampons or period cups.

All of our period underwear, swim, and activewear have our patented, 3-layer leakproof technology built right in

First layer: moisture-wicking, antimicrobial technology wicks away sweat and moisture while neutralizing odors to keep you fresh all day long.

Second layer: a super thin, highly-absorbent liner that holds the power of 3-12 tampons or pads.

Third layer: a secure, liquid-resistant outer layer keeps leaks from happening.

The short answer: nope! Depending on the level of absorbency of leakproof period underwear you choose and the heaviness of your flow, you can wear our period undies 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 to whatever youre already using on heavier days.

Do a quick rinse before you throw your underwear in the machine. Wash on cold with mild detergent then tumble dry on low. That's it! Be sure not to use softener or bleach and never iron... Not that you would.

If you’re not sure which size underwear to get, just book a Virtual Fitting and someone from the Knix team will video chat you to walk you through everything!

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!

How it works:

if your first order includes multiple period underwear: open, wash & wear one pair only to test them out. That way, in the unlikely event that you dont love them, any unopened packages from the same purchase can be exchanged or refunded back to you within 30 days of delivery (excluding original shipping fees).

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


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
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 635 reviews
  • 5 Stars
    524 Reviews
  • 4 Stars
    78 Reviews
  • 3 Stars
    10 Reviews
  • 2 Stars
    10 Reviews
  • 1 Star
    13 Reviews
96% of reviewers would recommend this product to a friend
Quality
Rated 4 out of 5
Comfort
Rated 4 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 4 out of 5
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
635 Reviews
Reviewed by Janine
Verified Buyer
Sleepover Short
Reviewing
Sleepover Short
I recommend this product
Rated 5 out of 5
Review posted

5 Stars from my 15 year old!

My daughter LOVES these shorts so much! She has always had sensitive skin and it gets irritated when using pads, so these are her go-to on her medium to light period days! She also uses them with a tampon on heavy days, and she never has to worry about accidents. She just asked me if I could buy a few more! I only wish they were a little cheaper....

Loading...
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
Was this helpful?
Reviewed by Missy
Verified Reviewer
Sleepover Short
Reviewing
Sleepover Short
I recommend this product
Rated 5 out of 5
Review posted

This is all my daughter will wear!

My daughter loves the traditional boy shorts because of the coverage, and this works for her. She wears them as underwear and swears by them. She doesn't wear a pad on her heaviest days. Please make these in more colors and LOTS OF THEM. We love them!

Loading...
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
Was this helpful?
Reviewed by Melodie S.
Verified Buyer
Sleepover Short
Reviewing
Sleepover Short
I recommend this product
Rated 5 out of 5
Review posted

Amazing

My daughter can wear a pair of these awesome undies all day at school. She sleeps all night without leaks or stained sheets. I wish I’d had these as teen.

Loading...
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
Was this helpful?
Reviewed by Sandra R.
Verified Reviewer
Sleepover Short
Reviewing
Sleepover Short
I recommend this product
Rated 5 out of 5
Review posted

No stained sheets

They do exactly what they say they do. I wore them on day 1 of my period when I usually leak through my pajamas and I woke up to no leaks at all.

Loading...
Was this helpful?
Reviewed by Caitie W.
Verified Reviewer
Sleepover Short
Reviewing
Sleepover Short
I recommend this product
Rated 5 out of 5
Review posted

Sleepover shorts to the rescue!

These shorts are so comfortable to sleep in! The extra long built in pad saved me from leaking. I could finally sleep comfortably on my period. Highly recommend!

Loading...
Was this helpful?