Cotton Modal Super Leakproof Full-Gusset Underwear Bikini

Black Friday Sale - Up to 60% off 

*Prices as marked. Exclusions apply. Offer valid from Wednesday, November 20th, 2025 to Monday, December 2, 2025 at 11:59PM PST. Early Access begins Tuesday, November 18, 2025. Offer available in-store and at knixteen.com. Up to 60% off sitewide; excludes gift cards, taxes, and shipping. Applies only to in-stock items and cannot be extended after the listed date. While supplies last; no rain checks. Orders follow Knixteen’s standard order change and cancellation policy. No price adjustments for previous orders. Cannot be combined with any other discount offers. Contact your local store for collection availability.  Items discounted 30% and below are eligible for size exchange or store credit. Items discounted above 30% are final sale and are not eligible for refunds, exchanges, or store credit.

“Flash Sale” refers to time-limited promotional pricing, a period set and determined by Knix; “Final Sale” refers to items sold on a non-returnable, non-exchangeable basis.

Period underwear are exempt from federal sales tax in Canada. They are also exempt from most provincial / harmonized sales taxes, subject to the following provincial sales tax rates which will apply to orders shipped to the following provinces and to orders purchased in retail stores located in the following provinces: BC/MB - 7% PST, SK - 6% PST. Exemptions apply to Knix and KT by Knix leakproof underwear and reusable leakproof pads.

Free Shipping available on orders over $80 CAD before tax and after discounts and applies to shipping addresses within Canada. Shipping timelines do not include processing times and are not guaranteed. It may take 1–4 business days to process your order. Contact your local store for collection availability. Knix store locations include Toronto (Queen St, Sherway Gardens, Premium Outlet, Yorkdale), Calgary (Mission, Market Mall), Vancouver (Robson, West 4th, Richmond Centre), Ottawa (Rideau Centre, Westboro), Edmonton (Southgate), Winnipeg (Polo Park). Knixteen may modify or cancel this promotion at any time.

What is your Sale Return Policy?

For items with a 20% or more discount, you may exchange for another item or return for store credit. No refunds can be accommodated. 

Items marked as “Flash Sale” or “Clearance” are final sale, meaning no returns, exchanges or refunds can be accommodated. No exceptions. 

Please note: Sale items are not eligible for our First Pair Risk-Free Policy.

View our full return and exchange policy here.

Do you offer price adjustments?

Unfortunately, we are unable to adjust the price on previous purchases. 

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.

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 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 you find your perfect fit. Book a video call with them today.