Super Leakproof Bikini

With the ability to hold up to 8 tampons or pads worth of blood, this super absorbent bikini can do it all—no backup needed. 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 8 tampons or pads.

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

the power of 8 tampons or pads, without all the bathroom breaks.
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Holds up to 8 tampons or pads worth of blood.
Thin, subtle, and designed to feel just like regular underwear.
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Rapidly absorbs moisture to keep you fresh and dry all day.
Antimicrobial layer kills bacteria and neutralizes smells.

With the ability to hold up to 8 tampons or pads worth of blood, this super absorbent bikini can do it all—no backup needed. 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 8 tampons or pads.

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

Main Body: 70% Nylon 30% Spandex  

Gusset Top Layer (Moisture Wicking + Anti-Odor): 87% Seaweed Fiber; 13% Modal  

Gusset 2nd Layer (Absorbent Fabric): 100% Polyester  

Gusset 3rd Layer Fresh Fix Technology 

Gusset 4th Layer (Waterproof Membrane): Polyurethane Film   

Free from PFAS and other chemical treatments.  

Machine wash cold with mild detergent, do not bleach, tumble dry on low.

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 Canada 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.  

Please note: orders placed on Friday after 1 pm will not be processed until the following Monday.  

FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
nothing is tmi here—we promise.
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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 you’re 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 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.



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 4.7 out of 5
Based on 282 reviews
  • 5 Stars
    236 Reviews
  • 4 Stars
    34 Reviews
  • 3 Stars
    3 Reviews
  • 2 Stars
    4 Reviews
  • 1 Star
    5 Reviews
98% 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
282 Reviews
Reviewed by Melissa Q.
Verified Buyer
I recommend this product
Rated 5 out of 5
Review posted

Excellent!

My daughter is able to wear these from morning until bed time even on her heaviest days. It is so nice for her not to have to worry about changing a pad every couple of hours at school (grade 6). Highly recommend!

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Reviewed by J h.
Verified Reviewer
I recommend this product
Rated 5 out of 5
Review posted

Best underwear ever

THESE UNDERWEAR REALLY WORK AND ARE AMAZING!! I'm 15 years old and have had my period since I was 10 years old. I have a very heavy period and normally have to worry about leaks all day long and change my pad at least every hour!! But I have no worries with these underwear and can wear them for about 24hrs without changing (even with sleeping in them)!! I was VERY sceptical since nothing else has worked for me, but now I am devastated I hesitated for this long, I wish I would have invested in these years ago! I now have 3 pairs of the oh no proof, 2 pairs of the super oh no proof, and 1 pair of the sleepover short underwear and I am planning on getting more! I went for the size M as I normally wear a size 2-4 pants, this size fits me perfect!! My mom loves them to as they are super easy to wash and care for and she doesnt have to help me get period out of all my outfits and underwear!! They are also environmentally friendly, I seriously havent made any waste for the last 5 periods, as i just wear and wash these!! Honestly you NEED these for yourself, you wont regret it trust me!!

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Reviewed by Jen
I recommend this product
Rated 5 out of 5
Review posted

I’m Converted!

WOW! WOW! WOW! That’s all I have to say after trying these undies. I’ve been a serial Always Infinity pad wearer for many years because this is what I felt confident would hold my period without any leaks. But, I’m officially converting to KT Super underwear! I wore these for almost 24 hours on a heavier day (overnight too) and no leaks! I’m literally amazed by how well these work, and they don’t even feel like your wearing a pad at all. There’s no wetness, no irritation, just period protection that I can count on.

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Reviewed by Jennifer G.
Verified Buyer
I recommend this product
Rated 5 out of 5
Review posted

My daughter loves them

My daughter is a gymnast. I bought her several different brands of period underwear and these were by far her favorite! She can wear a leotard and wear these with no worries during her practices.

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Reviewed by Sally G.
Verified Buyer
I recommend this product
Rated 5 out of 5
Review posted

We love these underwear

My

Daughters been wearing these even when she doesn’t have her period because they are comfortable. I would size up they run small.

Perfect for their period

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