Join Our Rewards Program
Earn rewards and exclusive member-only benefits for free.
Super Leakproof® Cotton Boybrief
Sale
Super Leakproof® Cotton Boybrief
$30.60
CAD
$36.00
15% off
Absorbs about 6 super tampons
Breathable cotton
More absorbency without the bulk
Machine washable
Size and Fit Guide
How to Measure
In order to select the correct sizing, we recommend you take the following measurements using a soft tape measure. If necessary, ask someone else to help.
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.
Hip
Stand with your feet together and measure around the fullest part of your hips and buttocks. Keep the tape level and snug, but not tight. The number where it meets is your hip measurement.
Rewards Members Earn
30 Points
You May Also Like
Comfort-First Fit
A mid-rise boyshort with full bum coverage.
Heavy Absorbency
Cozy Cotton-Blend
Soft cotton with a hint of spandex feels luxurious against your skin.
Worry-Free Protection
An innovative floating gusset provides leak protection from every angle.
Easy to Wash
Machine washable just like regular underwear.
Zoom
How to Choose?
Essential
- • Days you don’t need leak protection. Everyday freshness and moisture wicking.
-
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.
-
about 8-14 tsp
-
about 1.5-3 regular pads
-
about 4-7 super tampons
-
about 1.5-3 menstrual cups
Light
- • Daily freshness. For sweat, discharge, period spotting, or backup protection.
-
about 1-3 tsp
-
about 1-3 pantyliners
-
about 1-3 regular tampons
-
about 0.5 menstrual cups
Moderate
- • For mid-cycle flow, surprise cough or sneeze leaks, or a really sweaty spin class.
-
about 4-8 tsp
-
about 1-1.5 regular pads
-
about 2-4 super tampons
-
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.
-
about 15-20 tsp
-
about 1.5-2.5 super pads
-
about 7-11 super tampons
-
about 2-3 menstrual cups
Our Best-Selling Underwear
Shop All
Hot Deal 🔥
Super Leakproof® Dream Short™
$36.00
CAD
25% off
Color: Meadows Limited Edition
+2
Sale
Leakproof UltraThin No-Show High Rise
$22.40
CAD
20-30% off
Color: Lavender Limited Edition
+4
Final Hours ⏰
Super Leakproof® Dream Boxer™
$40.80
CAD
15% off
Color: Lavender Stripe Limited Edition
+1
Sale
Leakproof UltraThin No-Show Bikini
$18.90
CAD
20-30% off
Color: Meadows Limited Edition
+4
FRESH FIX TECHNOLOGY®
Cotton meets patented protection.
A sewn-in, floating liner soaks up about 6 super tampons’ worth of liquid—so you stay fresh, comfortable, and in control.
Soft Top Layer
Middle Layer
Leakproof Layer
Recently Viewed
How to wash
Knix underwear is 100% reusable and machine washable, just like your regular undies.
Not required. But for best results, you can rinse your leakproof with cold water in the tub or sink before washing.
Machine wash on a cold, gentle cycle with mild detergent.
For their longest life, air drying is best. Hang or lay flat to dry.
Fabric softeners, bleach, ironing, or heat from the dryer.
Total 5 star reviews: 12 Total 4 star reviews: 4 Total 3 star reviews: 4 Total 2 star reviews: 4 Total 1 star reviews: 2
62%would recommend this product
26 reviews
- Rated 5 out of 5 stars22 seconds agoLove
Great. Works for heavy periods
Melody F.Verified BuyerReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars4 days agoCotton boy brief
My first time trying the cotton boy briefs. They are very comfortable.
Roxanne H.Verified BuyerReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars1 week agoGreat product!
Comfortable and do not leak. Only drawback is they show through leggings. I really like them :-)
Alison W.Verified BuyerReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars2 weeks agoAwesome
Fits perfectly, no tugging, rising up, or sticking, plus has extra leakproof protection!
LORETTA H.Verified BuyerReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars3 weeks agoMy fav period underwear!
These are my favourite of all the period underwear cuts that I have tried. They are very comfortable, stay in place and no leaks. Full bum coverage too, which I like. Easy to clean. Absolutely love these!
Michelle H.Verified BuyerReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars3 weeks agoGreat choice for cotton!
Love the soft cotton The waist elastic has been changed from the last time I ordered these. Surprised me when I opened this package.
Christa H.Verified BuyerReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars1 month agoCotton
Very comfortable and fit well. Great leakage protection. I find the cotton more comfortable than the regular panties.
Leslie J.Verified BuyerReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars1 month agoSuper leakproof cotton boybrief
Good fit
Susan Z.Verified BuyerReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars1 month ago5 Stars
Great fit very comfortable
JadeReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars1 month ago5 Stars
The fabric is so soft and comfy! I love how it is stretchy and relaxed right away. I am someone who has thicker thighs and so sitting down for long periods of time wearing the BeyondSmooth fabric underwear is uncomfy for me because it digs in. I didn't feel that way with this style. When I'm on my period, I want to feel as comfy as possible so I really appreciated the true to size leg and waist openings on this style. I also loved the length on the front, it feels like a mid-rise on me which is how I would expect this style to sit.
Sarah P.ReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars1 month ago5 Stars
The boyshort style was very comfortable, fabric breathable and light weight. Great gusset coverage front and back.
Sihong Y.ReviewingSuper Leakproof® Cotton Boybrief - Rated 5 out of 5 stars1 month ago5 Stars
The one I wear tested was the boyshort - for my initial wear the waist and leg opening was comfortable, no pressing at all.
Sihong Y.ReviewingSuper Leakproof® Cotton Boybrief
