Leakproof Front-to-Back Liner Underwear Bikini

Designed with our longest gusset ever, it has full-coverage protection that goes all the way up the front, and all the way up the back, and absorbs the same as about 2.5 super tampons or 1 regular pad. Perfect for front sleepers, back sleepers, and everyone in between.

you asked, we made it, our widest gusset ever.
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Holds about 2.5 super tampons' or 1 regular pads' worth of blood.
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Texture feels smooth against the skin for added comfort.
Allows air to circulate to keep you cool and dry.
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Designed with our longest gusset ever, it has full-coverage protection that goes all the way up the front, and all the way up the back, and absorbs the same as about 2.5 super tampons or 1 regular pad. Perfect for front sleepers, back sleepers, and everyone in between.

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


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

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

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


Additional Product Ingredient Information

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.

For items with a 20% or more discount you may exchange for another item or store credit within 30 days of delivery. No refunds.

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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FOR THE PLANET
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FOR THIS GENERATION
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FOR THIS GENERATION
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FOR THE PLANET
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FOR THIS GENERATION
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FOR THE PLANET
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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 4.3 out of 5
Based on 46 reviews
  • 5 Stars
    36 Reviews
  • 4 Stars
    0 Reviews
  • 3 Stars
    3 Reviews
  • 2 Stars
    2 Reviews
  • 1 Star
    5 Reviews
78% 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
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Review posted
Reviewed by Arthur A.
Verified Buyer
Leakproof Front-to-Back Liner Underwear Bikini
Reviewing
Leakproof Front-to-Back Liner Underwear Bikini
Pant Size
Teen 18-20
Size Purchased
XXL
Usage
  • Incontinence
  • Sweat
Rated 5 out of 5

Effective Style

Like fuller protection/coverage. Wish had more colors, as when first offered style. Fit very good.

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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
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Review posted
Reviewed by Laurie M.
Verified Buyer
Leakproof Front-to-Back Liner Underwear Bikini
Reviewing
Leakproof Front-to-Back Liner Underwear Bikini
Pant Size
Teen 18-20
Size Purchased
M
Usage
  • Primary Protection
  • Period
Rated 5 out of 5

Amazing! The only period underwear you need!

I have been looking this for my daughter ever since she started her period. Regular period underwear is great but this is better! Even with regular underwear she had to wear a pad up the back and across the top at night time. Also, she loves to lounge around at home, and I had to constantly tell her to sit up so her period would stay in the area of the padding. This eliminates this problem. My only comment - which I think others have stated too - is more cheek coverage. Then, it would be perfect. This is just fine too for light day, heavy days, and all the days in between.

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Quality
Rated 5 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 5 out of 5
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Reviewed by Rebecca
Leakproof Front-to-Back Liner Underwear Bikini
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Leakproof Front-to-Back Liner Underwear Bikini
Rated 5 out of 5

5 Stars

I liked these more than any others I have ordered

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Reviewed by Pamela S.
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Leakproof Front-to-Back Liner Underwear Bikini
Reviewing
Leakproof Front-to-Back Liner Underwear Bikini
Rated 5 out of 5

Great period underwear

My daughter loves these, and they made her feel more secure during her period. Thanks for making a great product!

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Reviewed by Linda T.
Verified Buyer
Leakproof Front-to-Back Liner Underwear Bikini
Reviewing
Leakproof Front-to-Back Liner Underwear Bikini
Pant Size
Teen 18-20
Size Purchased
XL
Usage
  • Primary Protection
  • Period
Rated 5 out of 5

Panties

My great granddaughter loves them, because of the larger gusset. She is a stomach sleeper and a heavy bleeder

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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
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