Leakproof Underwear Bikini

A classic seamless bikini 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 3 tampons or pads.

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

like your comfiest underwear but with the power of 3 tampons or pads.
Image of a chrome heart surrounding text
Image of a absorbancy surrounding text
Holds up to 3 tampons or pads worth of blood.
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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.

A classic seamless bikini 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 3 tampons or pads.

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

Body: 77% Nylon, 23% LYCRA®

Gusset Liner: 86% Cotton, 10% Spandex, 4% Carbon

Gusset: Leakproof Technology

Free from PFAS and other chemical treatments.

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

We’ve extended our First Pair Risk-Free Policy* to give everyone a chance to try our new sizes. So even if it’s not your first order with Kt, you can return or exchange your period underwear until March 31, 2022. 

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. 

*Policy does not apply to sale or last call items.

We offer free 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.


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.

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 9–12 tsp (45–60 ml) of blood—that’s about 9–12 regular tampons or pads! Perfect for overnight protection or your heaviest days when changing into a fresh pair might not be convenient.


High Absorbency

Absorbs 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

Absorbs up to 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, swimwear, reusable pads, 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 3–20 tampons or pads.

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

The short answer: nope! Depending on the absorbency level of your period underwear and the heaviness of your flow, you can wear our period undies on their own or as a backup to pads, tampons, or menstrual cups. You can wear our High and Super absorbency underwear alone and be totally protected, while our Medium absorbency underwear can be worn alone on lighter days or as backup on heavier days.

Step 1: Give your 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 you find your perfect fit. Book a video call with them today.

We’ve extended our First Pair Risk-Free Policy* to give everyone a chance to try our new sizes. So even if it’s not your first order with Kt, you can return or exchange your period underwear until March 31, 2022.

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.

*Policy does not apply to sale or last call items.

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 1402 reviews
  • 5 Stars
    1161 Reviews
  • 4 Stars
    182 Reviews
  • 3 Stars
    28 Reviews
  • 2 Stars
    10 Reviews
  • 1 Star
    21 Reviews
97% 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
1402 Reviews
Reviewed by Angie C.
Verified Buyer
Leakproof Bikini
Reviewing
Leakproof Bikini
I recommend this product
Rated 5 out of 5
Review posted

Great panties - message needs amending

My daughter has not yet stated her period but I got these for her and me to try out, continue communication and to be prepared. They are super comfortable and look great. Leakage yet to be tested.

I would seriously urge you to consider amending the wording on the packaging though - using ‘the curse’ is way too negative and dated, even if it’s intended to be humorous. We really need to counter negativity about girls and women’s bodies and ensure the language is positive, empowering and celebratory.

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Reviewed by Claudia C.
Verified Buyer
Leakproof Bikini
Reviewing
Leakproof Bikini
I recommend this product
Rated 5 out of 5
Review posted

Great company /great customer service

I ordered one pair of underwear for my daughter. She wore and after a few hours she said they were comfortable so I ordered several more...$85.00 worth. I should have known better because she’s super sensitive and sure enough the next time she wore them she had complaints. I don’t think there was really anything wrong with the product she’s just really picky and I just think they weren’t a perfect fit for her. So a few days later the $85 order arrived. I didn’t open it and just contacted Knox about a return. They immediately gave me a refund without our me even returning all of the underwear. Then they sent me a really nice email saying that they gave me the 85 refund but that I could KEEP all of the products and give them to someone else or donate them to a women’s shelter. How nice is that?! Not many companies would do that. I’ll definitely be donating them my local women’s shelter.

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Reviewed by Rachel R.
Verified Buyer
Leakproof Bikini
Reviewing
Leakproof Bikini
I recommend this product
Rated 5 out of 5
Review posted

perfect for workouts

I’m not a teenager, but rather a smaller adult (late 30s) and I love these for everyday wear. I am super picky, and these are comfortable and perfect for workouts. Pay attention to the size chart, because it isn’t the same as standard girls OR women’s sizing. I normally wear a girls 14-16 or women’s 00-0 bottoms and a M fits perfectly.

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Reviewed by Morgan
Leakproof Bikini
Reviewing
Leakproof Bikini
I recommend this product
Rated 5 out of 5
Review posted

Worth it

I’m 22, 5’7 and weigh 120lbs. Up until now, I have been purchasing size Small on the Knix womens website. The M teen fits exactly the same and are SO much more cost effective. Bought the 5-pack of course! Hope to see more styles in the future (please make a Knixteen thong!)

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Reviewed by Happy Mama :.
Verified Buyer
Leakproof Bikini
Reviewing
Leakproof Bikini
I recommend this product
Rated 5 out of 5
Review posted

She loved them

My 13 year old daughter started her period this week and I just wanted to say how much she loved the underwear! I’m so happy that I purchased them a couple of months ago and had them ready for her first time. They made the day a whole lot easier.

She’s always had sensory issues and has dermatographia (hives if her skin is scratched) and was very relived to find that they were soft and didn’t irritate her skin.

She was nervous about going to school for the first time, but wearing these helped ease her anxieties and made her feel a lot more confident. They were a perfect fit under her dance leotard too :)

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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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