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Home / Up to 50% off Bikini Underwear / Leakproof UltraThin No-Show Bikini
Sale

Leakproof UltraThin No-Show Bikini

$21.60 CAD

$27.00

20-40% off
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Absorbs about 2.5 super tampons

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Invisible under clothes

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Moderate protection without the bulk

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Machine washable

Amber has 46” hips, and wearing KNIX L | Warm Sand

Amber has 46” hips, and wearing KNIX L

| Warm Sand
Amber has 46” hips, and wearing KNIX L | Warm Sand

Amber has 46” hips, and wearing KNIX L

Amber has 46” hips, and wearing KNIX L | Warm Sand

Amber has 46” hips, and wearing KNIX L

| General
| General
| General

Amber has 46” hips, and wearing KNIX L

Absorbency: Moderate

Moderate
Drop
Drop
Drop
Drop
Drop
about 2-4 super tampons
Essential
Drop
Drop
Drop
Drop
Drop
No Absorbency
Light
Drop
Drop
Drop
Drop
Drop
about 1-3 regular tampons
Heavy
Drop
Drop
Drop
Drop
Drop
about 4-7 super tampons
Ultra
Drop
Drop
Drop
Drop
Drop
about 7-11 super tampons

Color: Warm Sand

Size:

True to Size

•

Size:

Size and Fit Guide

Leakproof Underwear is Sales Tax Free in Canada*
Get FREE Express Shipping on all orders $125+

Shipping

HOLIDAY SHIPPING

Give the gift of Knix! To receive your order by Dec 24th, please order by the following dates.

Toronto, Ottawa, Montreal, Winnipeg, Regina, Calgary, Edmonton, Vancouver
Standard & Expedited: Monday, December 22

Urban Centres (excluding the above)
Standard: Wednesday, December 17
Express: Sunday, December 21

Rest of Canada
Standard: Sun, December 14*
Express: Thu, December 18*
*YK, NWT, NT, NL, and remote areas across Canada.

For locations serviced solely by Canada Post, please allow at least 5 additional days due to rotating strikes. This applies to P.O Box and RR addresses.

To avoid any additional delays during the rotating strikes, we will use alternate carriers when possible.

Please note: Weather conditions and carrier issues may cause delays. Delivery dates are not guaranteed.

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.
Year End Sale Return Policy

Returns

Returns

Sale & Last Call

Items discounted 30% and below are eligible for size exchange or store credit. Items discounted above 30% and above are final sale – no refunds, store credits, or exchanges can be accommodated.

Free Returns

Knix covers the return shipping fees for exchanges and refunds initiated through our Return & Exchange Portal. Exchange orders initiated through our Return & Exchange portal are also eligible for free shipping within the USA and Canada. Please note, the shipping fees on your original order are non-refundable.

Return Policy

Return policy varies by product, please check if your item is refund or exchange eligible by viewing our full policy here.
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"These are my favorite of all the period underwear styles I have tried, and I now own enough for a full cycle of wear."

- InStyle

Comfort-First Fit

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

Worry-Free Protection

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-Show Style

Made from our signature buttery soft fabric with a wide, comfortable waistband. Wear it on its own or under your favorite pajamas.

Easy to Wash

Machine washable just like regular underwear.

Zoom

Amber has 46” hips, and wearing KNIX L | Warm Sand
| Warm Sand
Amber has 46” hips, and wearing KNIX L | Warm Sand
Amber has 46” hips, and wearing KNIX L | Warm Sand
| General
| General
| General

How to Choose?

Essential

Drop
Drop
Drop
Drop
Drop
  • • Everyday Wear
  • • No leakproof protection
  • tsp
    0 tsp

Heavy

Drop
Drop
Drop
Drop
Drop
  • • heavy period days
  • • overnight protection
  • • light bladder leaks
  • 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

Drop
Drop
Drop
Drop
Drop
  • • light period days
  • • sweat
  • • discharge
  • tsp
    about 1-3 tsp
  • pad
    about 1-3 pantyliners
  • tampon
    about 1-3 regular tampons
  • cup
    about 0.5 menstrual cups

Moderate

Drop
Drop
Drop
Drop
Drop
  • • moderate period days
  • • light bladder leaks
  • • sweat
  • 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

Drop
Drop
Drop
Drop
Drop
  • • extra heavy period days
  • • overnight protection
  • • light bladder leaks
  • 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

Soft Top Layer

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

Our Best-Selling Underwear

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Leakproof UltraThin No-Show High Rise

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Light Leakproof No-Show Bikini

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4.5
Rated 4.5 out of 5 stars
Based on 594 reviews
Total 5 star reviews: 447 Total 4 star reviews: 61 Total 3 star reviews: 34 Total 2 star reviews: 25 Total 1 star reviews: 27
88%would recommend these products
ComfortRated 4.5 on a scale of 1 to 5
EffectivenessRated 4.5 on a scale of 1 to 5
FitRated -0.2 on a scale of minus 2 to 2
Ease of UseRated 4.7 on a scale of 1 to 5
Write a Review (Opens in a new window)
594 reviews
  • Rated 5 out of 5 stars
    3 minutes ago
    Happy

    Love being able to feel confident during the day. Knox makes a great product.

    Leslye P.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    2 hours ago
    Great so far!

    Bought these for my teenage daughter. So far so good!

    MELANIE H.
    Verified Buyer
    Was this helpful?
  • Rated 1 out of 5 stars
    5 hours ago
    They used to be so good.

    I bought these many years ago and loved them. I thought I should get some more because it couldn’t hurt. Got a medium, which is what I had gotten before and I couldn’t get them on. Returned for a large and to be honest I don’t think they are any different than the medium. I am not a large girl and they are squeezing me into oblivion. They are uncomfortable in every way imaginable.

    Stephanie A.
    Verified Buyer
    Was this helpful?
  • Rated 1 out of 5 stars
    2 days ago
    Very UN-comfy!

    I wanted to love these so much but the fabric is awful.. they are stiffer and scratchier somehow, with alot less flexibility and stretch in the fabric! And they are also made very small! My usual size was way too tight.

    Chelsey S.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    2 days ago
    Love these!

    This was a repeat order for me. I love these ultra thin undies. The leakproof moderate absorbency have better coverage in the front against leaks compared to the light absorbency.

    Rachel C.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    2 days ago
    New type but really nice!

    At first, I wasn’t impressed because these seemed very different from my previous undies……..but as I have NOW adjusted to a different style, I’m liking them more and more! They are comfortable and cute. They fit well, wash well and make me feel secure and happy to wear them! Thank you KNIX!!

    Barbara K.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    3 days ago
    Best Panties EVER!

    I love Knix. I love every product I’ve bought from them. It’s the best ever!

    Cynthia B.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    3 days ago
    Love them!

    They are so comfortable. Great fit! And the leakproof works perfectly. I’ve switched entirely to this set!

    Sarah M.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    3 days ago
    The only underwear!

    No show comfortable and leak protection all in one

    BARBARA R.
    Verified Buyer
    Was this helpful?
  • Rated 3 out of 5 stars
    3 days ago
    3 Stars

    Still waiting to see how these go, the fit is good though.

    Jessica
    Was this helpful?
  • Rated 2 out of 5 stars
    3 days ago
    Quality isn’t as it should be and they run super small

    I have loved Knix over the last few years. I decided to take advantage of their recent sale and was disappointed in many of the undies I received. They are size Medium and all are bikini but they vary in size and some of the material feels cheap and different than normal.

    Susan P.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    3 days ago
    Comfy, sleek and secure

    Love them!

    Sarah I.
    Verified Buyer
    Was this helpful?