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Teen Leakproof UltraThin No-Show Bikini

$25.00 CAD

Buy 3+ Save 15%, Buy 5+ Save 20%

Absorbs about 2.5 super tampons

Invisible under clothes

Superior protection without the bulk

Machine washable

| Warm Sand
| Warm Sand
| Warm Sand
| General
| General
| General
| General
| General

Color: Warm Sand

Size:

True to Size

Size:

Size and Fit Guide

Leakproof Underwear is Sales Tax Free in Canada*

Build Your 3-Pack

Teen Leakproof UltraThin No-Show Bikini

Color: Warm Sand

Size:

Size:

Teen Leakproof UltraThin No-Show Bikini

Color: Warm Sand

Size:

Size:

Teen Leakproof UltraThin No-Show Bikini

Color: Warm Sand

Size:

Size:

Free Shipping on orders $100+

Shipping

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.

Delivery Time

For the most up-to-date delivery time estimates, please refer to the shipping timeline at checkout. Delivery timelines vary depending on location and do not include processing times.

Shipping Charges

Orders over $100* CAD = Free Shipping (2-6 business days)

Orders under $100* CAD = $12 CAD Shipping (1-3 business days)

Orders delivering to NWT, Nunavut and Yukon are subject to $20 delivery fee.

*After discounts, before shipping and taxes.

First Pair Risk Free for 30 Days

Leakproof Underwear, Risk Free

Returns & Exchanges

New to leakproof? Your first pair is risk free for 30 days. Wear them, wash them, and see how they work for your body. Not right for you? We'll refund the item price (original shipping excluded). Prefer a different size or style? We also offer free exchanges. Just email info@knix.com and we'll take care of you.

Purchased leakproof before? Within 30 days of delivery you can exchange for another size, style, or store credit. We're unable to provide refunds on underwear. If you ordered multiple pairs, please open, wash, and wear one pair only before initiating an exchange.

Still have questions? View our full policy here.

Rewards Members Earn 25 Points

Product Description

Hanging out or running to your next class? These period undies provide the ultimate comfort you want, plus ultra-thin protection you need from sweat, discharge and leaks. It’s a classic silhouette made with a super soft-and-stretchy, quick-drying material. It absorbs about the equivalent of 2.5 super tampons for an extra dose of confidence on those medium-flow days.

Comfort-First Fit

Bikini silhouette with a classic mid-rise fit, medium hip and bum coverage.

Worry Free Protection

Our newest leakproof innovation provides more absorbency without the bulk. Patented 360 LeakSeal™ technology locks in leaks at every edge.

Moderate Absorbency

Absorbs 2.5 super tampons worth of liquid—perfect for moderate flow days, light bladder leaks, and sweat. The carbon cotton gusset top layer keeps you dry.

No More Panty Lines

Made from our signature buttery-soft fabric and designed to be invisible under clothes, including leggings.

Easy to Wash

Machine washable just like regular underwear.

Zoom

| Warm Sand
| Warm Sand
| Warm Sand
| General
| General
| General
| General
| General

How to Choose?

Essential

  • Days you don’t need leak protection. Everyday freshness and moisture wicking.
  • tsp
    0 tsp

Heavy

  • Extra peace of mind. For the first days of your cycle, light bladder leaks, or a full night's sleep without a leak.
  • tsp
    about 8-14 tsp
  • pad
    about 1.5-3 regular pads
  • tampon
    about 4-7 super tampons
  • cup
    about 1.5-3 menstrual cups

Light

  • Daily freshness. For sweat, discharge, period spotting, or backup protection.
  • tsp
    about 1-3 tsp
  • pad
    about 1-3 pantyliners
  • tampon
    about 1-3 regular tampons
  • cup
    about 0.5 menstrual cups

Moderate

  • For mid-cycle flow, surprise cough or sneeze leaks, or a really sweaty spin class.
  • tsp
    about 4-8 tsp
  • pad
    about 1-1.5 regular pads
  • tampon
    about 2-4 super tampons
  • cup
    about 0.5-3 menstrual cups

Ultra

  • Ultimate peace of mind. For the heaviest period days, light bladder leaks, unexpected postpartum flow, or overnight protection.
  • tsp
    about 15-20 tsp
  • pad
    about 1.5-2.5 super pads
  • tampon
    about 7-11 super tampons
  • cup
    about 2-3 menstrual cups
FRESH FIX TECHNOLOGY®

Built-in protection that feels like nothing at all.

Our patented 360 LeakSeal™ technology locks in leaks at every edge. The ultra-thin liner absorbs about 2.5 super tampons worth of liquid.

Soft Top Layer

Gently wicks away moisture while keeping you feeling fresh and odor-free.

4.4
Rated 4.4 out of 5 stars
Based on 752 reviews
Total 5 star reviews: 549 Total 4 star reviews: 77 Total 3 star reviews: 48 Total 2 star reviews: 32 Total 1 star reviews: 46
Reviews Summary
Customers say these period underwear are comfortable and provide effective protection without the bulk of traditional pads. Many appreciate the soft, buttery fabric that feels like regular underwear and the no-show design under clothing. Users frequently mention confidence during workouts, daily activities, and even swimming. Parents often purchase these for teenage daughters who love the comfort and security they provide. Common feedback includes praise for the absorbency and leak-proof performance. However, several reviews mention sizing inconsistencies, with some finding recent purchases run smaller than previous orders. A few customers note the leg holes can feel tight or that the fit varies between different fabric types.
85%would recommend these products
ComfortRated 4.5 on a scale of 1 to 5
FitRated -0.1 on a scale of minus 2 to 2
EffectivenessRated 4.6 on a scale of 1 to 5
Keywords
Keywords
Rating
Ratings
Height
Height
Usual Pant Size - Knixteen
Usual Pant Size - Knixteen
Size Purchased - Knixteen Underwear
Size Purchased - Knixteen Underwear
752 reviews
  • Rated 5 out of 5 stars
    1 hour ago
    Very comfortable

    I have been excited to try ever since the birds papaya shared these. They are even better than I thought they’d be!

    Catie S. J.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    4 hours ago
    Great for autistic tween

    These are great for a child with special needs who gets overwhelmed with period products.

    Kelly B.
    Verified Buyer
    Reviewing
    Teen Leakproof UltraThin No-Show Bikini 3-Pack
  • Rated 5 out of 5 stars
    18 hours ago
    Better than I expected

    Can't wait to order more. I have tried a couple other "period panties" and these by Knix arw by far the best!

    Amanda F.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    21 hours ago
    Cute print comfy fit

    Absolutely love the print I got on these and they fit so wonderfully now that I've figured out my sizing

    Alexandra B.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    Yesterday
    great

    perfect

    Julie L.
    Verified Buyer
    Reviewing
    Teen Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    2 days ago
    AprilO

    Leakproof underwear great for light bladder leaks

    April O.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    2 days ago
    Leakproof

    Great for light bladder leaks

    Cindy O.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    2 days ago
    Absolute Favourite

    While I’m writhing in pain, the last thing I want to worry about is leaking. This product has given me comfort and ease of mind.

    April J.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    3 days ago
    Love them!

    They work well, are comfy, can throw them in the wash, and no-show.

    Caitlin F.
    Verified Buyer
    Reviewing
    POS - Leakproof UltraThin No-Show Bikini Shimmer 3-Pack - Last Call
  • Rated 5 out of 5 stars
    3 days ago
    Amazing

    Can't say enough about these panties. They absolutely deliver what is promised. So comfortable it feels like you are wearing nothing!!

    On those hot and humid days when you are working out or working hard these are the best to wick away that unwanted moisture.

    Dianna N.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    4 days ago
    Awesome leakproof

    Love my no show leakproof panties.

    Meryana V.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini
  • Rated 5 out of 5 stars
    4 days ago
    Perfect feel and fit

    These are my favorite undies!

    Jill J.
    Verified Buyer
    Reviewing
    Leakproof UltraThin No-Show Bikini