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Super Leakproof® Sleepover Boxer
Super Leakproof® Sleepover Boxer
38 ReviewsBundle & Save

Super Leakproof® Sleepover Boxer

$45.00
$45.00USDBuy 3+ SAVE 15%, Buy 5+ SAVE 20%
✓Absorbs about 7-9 super tampons✓Built in leakproof underwear✓Optimal overnight protection✓OEKO-TEX® Certified✓Machine washable
Absorbency: Heavy
Compare to Pads & Tampons

Light

• Ideal for lightest period days, spotting, sweat and discharge.

  • about 1-3 tsp
  • about 1-3 pantyliners
  • about 1-3 regular tampons
  • about 0.5 menstrual cups

Moderate

• Ideal for medium period days, discharge and sweat.

  • about 4-8 tsp
  • about 1-1.5 regular pads
  • about 2-4 super tampons
  • about 0.5-3 menstrual cups

Heavy

• Perfect for overnight protection or your teens heaviest days when changing into a fresh pair might not be convenient.

  • about 8-14 tsp
  • about 1.5-3 regular pads
  • about 4-7 super tampons
  • about 1.5-3 menstrual cups

Ultra

• Our longest front-to-back liner, designed for their heaviest flow days and overnight protection.

  • about 15-20 tsp
  • about 1.5-2.5 super pads
  • about 7-11 super tampons
  • about 2-3 menstrual cups
Color
Size
True to Size
Size and Fit Guide

Size Guide

SizeHip (In)Kids Pant SizeAdult Pant Size
XXS25 - 277---
XS28 - 308 - 10---
S31 - 3412 - 1400 - 2
M35 - 3816 - 204 - 8
L39 - 42---10 - 14
XL43 - 46---16 - 18
XXL47 - 50---20 - 22

How to Measure

Waist
Measure around the narrowest part of your torso, usually just above your belly button. Keep the tape snug and level, but not tight. The number where it meets is your waist measurement.

Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.
Shipping

Processing Timelines

Please allow 1-2 business days for our warehouse team to pack and ship your order. During peak periods such as sales, holidays and product launches, please allow up to 4 business days for us to process your order. Once an order is placed, we cannot guarantee any address updates, order changes or cancellations. Orders placed on Friday after 1PM will not be shipped until the following Monday.

Most orders will ship from a single warehouse. However, we occasionally ship from a combination of warehouse locations, so you may receive your order in multiple parts. If items from your order ship in separate packages, we’ll send you tracking information for each package when it becomes available.

Delivery Timelines

For the most up to date delivery time estimates, please refer to the shipping timeline at checkout. All transit times are measured in business days which are Monday-Friday, excluding holidays.

Please note, all shipping timelines are estimates and are not guaranteed.

Canadian Orders

Orders within Canada will be shipped with Canada Post or Purolator based on your address and carrier availability.

Standard Canadian shipping is free on eligible orders over $80 CAD*. Orders under $80 CAD are $12 CAD for standard shipping. Orders delivering to NWT, Nunavut, and Yukon under $100 CAD* are $20 CAD for standard Canada shipping.

*After discounts, before shipping and taxes

Return Policy

Return policy varies by product, please check if your item is refund or exchange eligible by viewing our full policy here.

Leakproof Underwear is Sales Tax Free in Canada

Good news, period underwear and pads are exempt from federal sales tax in Canada, and most provincial/harmonized sales taxes too. The exception? If your order ships to (or you're shopping in a store in) British Columbia or Manitoba, a 7% PST applies. Saskatchewan, it's 6% PST.

"Super comfy and move-proof. I went from skeptical to wanting a pair in every style. They make period-stress a thing of the past."

'- Kayla A

Build Your Bundle & Save

Super Leakproof® Sleepover Short
Super Leakproof® Sleepover Short
$40.00 USD
Super Leakproof® Mini Sleepover Boxer
Super Leakproof® Mini Sleepover Boxer
$45.00 USD
SuperPlus Leakproof® Sleepover Short
SuperPlus Leakproof® Sleepover Short
$45.00 USD
Super Leakproof® No-Show Bikini
Super Leakproof® No-Show Bikini
$27.00 USD

Comfort-First Fit

Combining a loose-fitting boxer with an internal brief for discreet Leakproof protection. Designed to be worn as both loungewear and overnight protection. Designed specifically for teens and tweens, so may fit smaller than styles made for adults.

Worry Free Protection

Designed with a built-in leakproof liner that fits snug to the body, it helps lock in leaks from every angle, even as you toss and turn.

Absorbency Level: Heavy

Absorbs 7-9 super tampons' worth of liquid for overnight protection and heavy flow days.

Wear. Wash. Repeat.

100% reusable and machine washable, just like regular underwear.

OEKO-TEX® Certified

Textiles you can trust. OEKO-TEX® STANDARD 100 | [HK020 246396] [TESTEX AG]

OEKO-TEX® STANDARD 100 sets the standard for textile safety, from yarn to finished product. Every product carrying the label has passed laboratory tests for harmful substances.

Machine Washable

Wash with like colors on a cold cycle using a mild detergent. Do not bleach, dry clean, or iron. Lay flat to dry.

Fabric

Body: 48% Polyester, 47% Rayon from Bamboo, 5% Spandex;
Liner: 96% Cotton, 4% Spandex;
Fresh Fix Technology® Gusset:
Gusset 1: 92% Polyester, 8% Spandex;
Gusset 2: 95% Polyester, 5% Spandex;
Gusset 3: 95% Polyester, 5% Spandex; 100% Polyurethane

OEKO-TEX® Certified

Textiles you can trust. OEKO-TEX® STANDARD 100 | [HK020 246396] [TESTEX AG]

OEKO-TEX® STANDARD 100 sets the standard for textile safety, from yarn to finished product. Every product carrying the label has passed laboratory tests for harmful substances.

FREE Shipping on orders over $80

Eligible for a return or exchange within 30 days of delivery and with original packages and all tags attached.
 

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Ordered

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Delivered

How it compares

Leakproof layers illustration
LOVED BY TEENS. TRUSTED BY PARENTS.

Why leakproof?

Built-in protection that helps teens feel secure on their period. The science behind the #1 Leakproof Brand in North America.
Soft top layer

Soft top layer

Comfy, super smooth moisture-wicking liner keeps you feeling fresh and dry.
Middle absorbent layer

Middle absorbent layer

An absorbent layer holds up to 9 super tampons worth of blood.
Bottom leakblocker layer

Bottom leakblocker layer

Outer layer acts as a barrier to stop any leaks from getting through.
How to wash

How to wash

Kt period undies are 100% reusable and machine washable. Throw them in the wash just like regular undies.

Easy to Wash

100% reusable and machine washable, just like regular underwear.

Customer Reviews

4.7 ★★★★★ Based on 38 reviews
Write a Review
Keywords
ComfortFitLeak ProtectionAbsorbencyDesignQualityValue
Rating
★★★★★★★★★★★★★★★
38 reviews
Ellie C. Verified Buyer ●
★★★★★

Cute

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Comfortable Verified Buyer ●
★★★★★

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Competent Verified Buyer ●
★★★★★

I’m not a fan of the Knix’s Women styles so I picked the Teen line instead and it still works. These are great for sleeping in and even in the morning when my period is at its heaviest.

22 hours ago

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Therese A. Verified Buyer ●
★★★★★

The favorite

PJ’s

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casual hanging out or even running around with friends if you are a teen. Absolute favorite. Verified Buyer ●
★★★★★

1 month ago

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Jennifer C. Verified Buyer ●
1 month ago
★★★★★

Amazing!

Well made and great idea for sleepovers!

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Isabel S. Verified Buyer ●
2 months ago
★★★★★

Very comfy!

I really enjoyed sleeping in these sleep shorts during my period they're so comfy! I would sleep in these even when i'm not on my period.

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Melissa Verified Buyer ●
2 months ago
★★★★★

5 Stars

These are so cute and discrete. Fits true to size.

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Corina Verified Buyer ●
3 months ago
★★★★★

5 Stars

A little on the big side compared to same size swim bottoms.

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Your questions, answered.

Good news, period underwear and pads are exempt from federal sales tax in Canada, and most provincial/harmonized sales taxes too. The exception? If your order ships to (or you're shopping in a store in) British Columbia or Manitoba, a 7% PST applies. Saskatchewan, it's 6% PST. Still have questions? We've got more info here.

Pretty simple, actually! Each pair has a built-in liner that absorbs period blood, no pads or tampons needed. KT Period Underwear comes in light, moderate, and heavy absorbency, so no matter what your teen's flow looks like, there's a pair made for them.

Ultra: Absorbs the equivalent of 7-11 super tampons. Our longest front-to-back liner, designed for their heaviest flow days and overnight protection.

Heavy: Absorbs the equivalent of 4–7 super tampons. Great for overnight or the heaviest days when swapping into a fresh pair isn't always an option.

Moderate: Absorbs about 2.5 super tampons' worth. A solid go-to for medium flow days, discharge, and sweat.

Light: Absorbs about 1 regular tampon's worth. Perfect for spotting, lightest days, discharge, and sweat.

Totally up to them! Every flow is different, and there's no wrong answer. Depending on the absorbency level and how heavy their period is, they can wear KT undies on their own or use them as backup alongside a tampon or menstrual cup.

It's easy, we promise. Give them a quick rinse under cold water first, then toss them in the washing machine with your regular clothes, cold water, mild detergent, no softener or bleach. For drying: lay flat for medium absorbency styles, or tumble dry on low for high and super absorbency ones.

For most teens, yes! Our Heavy and Super absorbency styles are made for exactly that.