Cotton Modal Super Leakproof Full-Gusset Underwear Bikini - Clearance

Our most-requested style is finally here! Designed with our widest gusset ever, it has full-coverage protection that goes all the way up the front, and all the way up the back. Perfect for front sleepers, back sleepers, and everyone in between.

First layer: Moisture-wicking, odor-crushing technology wicks away sweat and moisture while neutralizing smells 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.

Fourth layer: Acts like a waterproof membrane to prevent leaks on the outside.

you asked, we made it, our widest gusset ever.
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Holds up to 8 tampons or pads worth of blood.
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Texture feels smooth against the skin for added comfort.
Anti-odor layer fights smells and bacteria.
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Allows air to circulate to keep you cool and dry.

Our most-requested style is finally here! Designed with our widest gusset ever, it has full-coverage protection that goes all the way up the front, and all the way up the back. Perfect for front sleepers, back sleepers, and everyone in between.

First layer: Moisture-wicking, odor-crushing technology wicks away sweat and moisture while neutralizing smells 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.

Fourth layer: Acts like a waterproof membrane to prevent leaks on the outside.

Body: 47% Cotton, 47% Modal, 6% Spandex

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

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


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 for 30 days! Learn more about our First Pair Risk-Free Policy.

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.

Nothing is TMI here—we promise.
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Black Friday Sale - Up to 60% off 


*Prices as marked. Exclusions apply. Offer valid from Wednesday, November 20th, 2025 to Monday, December 2, 2025 at 11:59PM PST. Early Access begins Tuesday, November 18, 2025. Offer available in-store and at knixteen.com. Up to 60% off sitewide; excludes gift cards, taxes, and shipping. Applies only to in-stock items and cannot be extended after the listed date. While supplies last; no rain checks. Orders follow Knixteen’s standard order change and cancellation policy. No price adjustments for previous orders. Cannot be combined with any other discount offers. Contact your local store for collection availability.  Items discounted 30% and below are eligible for size exchange or store credit. Items discounted above 30% are final sale and are not eligible for refunds, exchanges, or store credit.


“Flash Sale” refers to time-limited promotional pricing, a period set and determined by Knix; “Final Sale” refers to items sold on a non-returnable, non-exchangeable basis.


Period underwear are exempt from federal sales tax in Canada. They are also exempt from most provincial / harmonized sales taxes, subject to the following provincial sales tax rates which will apply to orders shipped to the following provinces and to orders purchased in retail stores located in the following provinces: BC/MB - 7% PST, SK - 6% PST. Exemptions apply to Knix and KT by Knix leakproof underwear and reusable leakproof pads.


Free Shipping available on orders over $80 CAD before tax and after discounts and applies to shipping addresses within Canada. Shipping timelines do not include processing times and are not guaranteed. It may take 1–4 business days to process your order. Contact your local store for collection availability. Knix store locations include Toronto (Queen St, Sherway Gardens, Premium Outlet, Yorkdale), Calgary (Mission, Market Mall), Vancouver (Robson, West 4th, Richmond Centre), Ottawa (Rideau Centre, Westboro), Edmonton (Southgate), Winnipeg (Polo Park). Knixteen may modify or cancel this promotion at any time.


What is your Sale Return Policy?


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.


View our full return and exchange policy here.


Do you offer price adjustments?


Unfortunately, we are unable to adjust the price on previous purchases. 

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.

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 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.

Reviews
average rating 4.3 out of 5
Based on 8 reviews
  • 5 Stars
    4 Reviews
  • 4 Stars
    2 Reviews
  • 3 Stars
    2 Reviews
  • 2 Stars
    0 Reviews
  • 1 Star
    0 Reviews
75% 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
Review posted
Reviewed by Kimberly G.
Verified Buyer
Pant Size
Kids 8-10
Size Purchased
XS
Usage
  • Back-up Protection
  • Period
  • Primary Protection
Rated 5 out of 5

Trustworthy coverage

I bought these for my 11 yr old granddaughter. She says they are comfy and she doesn’t have to worry about leaking when wearing them.

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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
Was this helpful?
Review posted
Reviewed by Lisa F.
Verified Buyer
I'm a...
Teenager
I purchased for...
A Teenager/Tween
Pant Size
Kids 8-10
Size Purchased
XS
Usage
  • Other
Rated 5 out of 5

Great Cover

Such good coverage.

Less worry!

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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
Was this helpful?
Review posted
Reviewed by Vanessa C.
Verified Buyer
I'm a...
Parental Figure
I purchased for...
A Teenager/Tween
Pant Size
Teen 4-10
Size Purchased
M
Usage
  • Primary Protection
Rated 5 out of 5

Great coverage!

No leaks with full coverage front and back!

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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
Was this helpful?
Review posted
Reviewed by Jennifer H.
Verified Buyer
I'm a...
Parental Figure
I purchased for...
A Teenager/Tween
Pant Size
Teen 4-10
Size Purchased
S
Usage
  • Period
  • Primary Protection
Rated 5 out of 5

Bought for my daughter

She’s super happy with these. The extra absorption means she’s not waking up at night or worried at school.

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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 4 out of 5
Was this helpful?
Review posted
Reviewed by LaToya M.
Verified Buyer
I'm A...
Adult
I purchased for...
Myself
Pant Size
Teen 18-20
Size Purchased
XL
Usage
  • Back-up Protection
Rated 4 out of 5

Full gusset gal

I really enjoyed my experience with this undergarment. As a full figured gal I was always concerned about leaking during menses. These cover your areas completely minimizing your risk of leaks.

Loading...
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 4 out of 5
Was this helpful?