Skip to content

Your Bag

Your cart is empty

But you're full of potential..

Create an account to join Club Knix and earn points on this order
Selling Fast 🔥

Ultra Leakproof Zones+® Bikini

$21.60 CAD

$36.00

40% off

Absorbs about 9 super tampons

Invisible under clothes

Extended gusset for extra protection

Machine washable

| Black
| Black
| Black
| Black
Made with soft, stretchy fabric that’s quick dry for your comfort | General

Made with soft, stretchy fabric that’s quick dry for your comfort

Designed with extra long protective coverage in the front & back | General

Designed with extra long protective coverage in the front & back

Washes just like regular underwear | General

Washes just like regular underwear

Color: Black

Size:

True to Size

Size:

Size and Fit Guide

Leakproof Underwear is Sales Tax Free in Canada*
Spend $100, get Free Priority Fulfillment

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 21 Points

"When Mother Nature decides to bless you with her presence on leg day, bust out this pair for a workout that’s as comfortable as possible."

- InStyle

Product Description

Experience maximum absorbency and confident protection with the Knix Ultra Leakproof Zones+® Bikini, designed with an extra‑long liner and patented 360 LeakSeal™ technology to absorb about 9 super tampons’ worth of liquid — ideal for heavy period days, overnight protection, and light bladder leaks. Made from soft, quick‑dry, buttery‑soft PerformaStretch® fabric that lies invisible under clothes, this mid‑rise bikini silhouette delivers a comfortable fit with medium hip and bum coverage and easy machine‑washable care. With extended protective coverage front and back and dependable leakproof performance built into every edge, it’s a trusted choice for everyday confidence and comfort.

Comfort-First Fit

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

Worry-Free Protection

Our most absorbent underwear features an extra-long liner that runs high in the front and up the back. Patented 360 LeakSeal™ technology provides leakproof protection at every edge.

Ultra Absorbency

Absorbs 9 super tampons worth of liquid—great for heavy flow days, overnight protection, and light bladder leaks.

No-Show Style

Made from our signature buttery-soft PerformaStretch® fabric, it appears invisible under clothing.

Easy to Wash

Machine washable just like regular underwear.

Zoom

| Black
| Black
| Black
| Black
Made with soft, stretchy fabric that’s quick dry for your comfort | General
Designed with extra long protective coverage in the front & back | General
Washes just like regular underwear | 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.

Absorbs about 7-9 super tampons worth of liquid.

Soft Top Layer

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

4.1
Rated 4.1 out of 5 stars
Based on 462 reviews
Total 5 star reviews: 286 Total 4 star reviews: 50 Total 3 star reviews: 44 Total 2 star reviews: 28 Total 1 star reviews: 54
77%would recommend these products
ComfortRated 4.1 on a scale of 1 to 5
EffectivenessRated 4.2 on a scale of 1 to 5
FitRated 0.1 on a scale of minus 2 to 2
462 reviews
  • Rated 5 out of 5 stars
    2 months ago
    Period proof

    My daughter prefers to wear Knix period underwear than pads now.

    Lorna H.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini - Sale
  • Rated 5 out of 5 stars
    2 months ago
    Overnight confidence

    I love these. I can sleep without worrying about the sheets. They also feel like regular underwear, so they are comfortable to wear as well.

    Mélissa R.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini Kit
  • Rated 5 out of 5 stars
    3 months ago
    Ultra Leakproof

    Loved them

    Janet F.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini
  • Rated 5 out of 5 stars
    3 months ago
    Great fit and no leaks

    These fit wonderful and do not leak

    Devaney W.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini Kit
  • Rated 5 out of 5 stars
    3 months ago
    Great!

    Terrific bikini. I was worried that it would be too bulky with the thicker pad, but it's not.

    Hollis K.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini Kit
  • Rated 5 out of 5 stars
    3 months ago
    Great!

    Terrific! I was worried that it would be too bulky but it's not.

    Hollis K.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini Kit
  • Rated 5 out of 5 stars
    3 months ago
    Very comfortable

    Fit nice

    Harley H.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini
  • Rated 5 out of 5 stars
    3 months ago
    Awesome

    Love them !!!!

    Marie-Eve P.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini
  • Rated 5 out of 5 stars
    3 months ago
    Heavy day go to

    My new favorite pair for my heavy days. Very comfortable and it really doesn’t show under clothes and has a barely there feel

    Cara H.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini
  • Rated 5 out of 5 stars
    3 months ago
    Perfect product

    Nice size and protect 100 % is the best im not woory any more for accidents

    Olga V.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini
  • Rated 5 out of 5 stars
    3 months ago
    excellent

    excellent

    Donnie H.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini
  • Rated 5 out of 5 stars
    3 months ago
    Love these!!

    These are very comfy!! I can't wait to get more!!

    Monica R.
    Verified Buyer
    Reviewing
    Ultra Leakproof Zones+® Bikini

Your underwear questions, answered.