Ultra-soft cotton boxer brief featuring extra leg length and our longest super leakproof gusset ever. Absorbs up to 10 tampons or pads worth of blood!
First layer: Moisture-wicking technology wicks away sweat and moisture while neutralizing odors to keep you fresh all day long.
Second layer: A super thin, highly-absorbent liner that holds the power of 10 tampons or pads.
Third layer: A secure, liquid-resistant outer layer keeps leaks from happening.
Ultra-soft cotton boxer brief featuring extra leg length and our longest super leakproof gusset ever. Absorbs up to 10 tampons or pads worth of blood!
First layer: Moisture-wicking technology wicks away sweat and moisture while neutralizing odors to keep you fresh all day long.
Second layer: A super thin, highly-absorbent liner that holds the power of 10 tampons or pads.
Third layer: A secure, liquid-resistant outer layer keeps leaks from happening.
Machine wash cold with mild detergent, do not bleach, tumble dry on low.
Body: 47% Cotton, 47% Modal, 6% Spandex
Lining: 84% Modal, 8% Seaweed, 8% Spandex
Gusset: Leakproof Technology®, 100% Polyester, PU Film
FINAL SALE
Items marked as “Black Friday Deal", “Clearance” or “Vault Sale” are final sale, meaning no returns, exchanges or refunds can be accommodated.
We offer free standard shipping on all orders over $70. We ship our items via DHL or Canada Post depending on your location. Please allow 1-2 business days for your items to be processed and shipped. During high volume periods, your order may take up to 7 business days to dispatch from our warehouse location.
US Orders: Please allow 3–10 business days for orders to arrive.
International Orders: Please allow 10–25 business days for orders to arrive.
NOTE: Orders placed on Friday after 1 PM will not be processed until the following Monday.
CANADIAN CUSTOMERS: Shop www.knixteen.ca to order in Canadian currency.
Super Absorbency
A total replacement for disposable period products - absorbs approximately 8 tsp, 40 ml, or the equivalent of 8 regular tampons worth of liquid.
High Absorbency
Ready to stop leaks whenever - absorbs approximately 4-6 tsp, 20-30 ml, or the equivalent of 4-6 tampons worth of liquid.
Medium Absorbency
Confident backup protection for heaviest days - absorbs approximately 3 tsp, 15 ml, or the equivalent of 2 tampons worth of liquid.
Our Period Underwear features triple layer technology that ensures you stay fresh, dry, and protected. The anti-odor top layer wicks away moisture from your skin; the inner-layer absorbs the liquid and locks it in; and the leak resistant outer layer keeps any liquid from spotting your clothes.
Depending on the level of absorbency of leakproof period underwear you choose and the heaviness of your flow, you can wear our period panties on their own or as backup protection along with a pad or tampon. You're totally protected with our high and super absorbency leakproof underwear, while our low and medium absorbency leakproof underwear can replace pads and tampons on lighter days and work great as a backup for your usual period protection on heavier days.
Washing your period underwear shouldn't be complicated, so we designed our products to be super easy to wash and care for. For best results, machine wash on cold with mild detergent and tumble dry on low (Super Leakproof Underwear). That's it! Pro tips: Don't use softener or bleach and never iron.
If you want help finding the perfect Period Underwear product size for you, connect with one of our expert Knix team members for a 1-on-1 fitting session over video chat. Book a time that’s convenient for you, and we’ll walk you through everything!
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We have a First Pair Risk-Free Return Policy for your first order - no ifs ands or buts! So if you ordered the wrong size of Period Underwear, we’ll send you a different pair at no cost or offer you a standard refund within 30 days of delivery (excluding original shipping fees).
If your first order included multiple Period Underwear: OPEN, WASH & WEAR ONE PAIR ONLY to be sure you love them. That way if you don’t, any unopened packages from the same purchase are also eligible for an exchange or standard refund (excluding original shipping fees).
All unopened packages will be donated to local organizations to support people in need.
| Fit |
Rated 0 on a scale of minus 2 to 2, where minus 2 is Runs Small, 0 is True to Size and 2 is Runs Large
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These might not be the most attractive undies I own but they are the best. These are the only menstrual product that I’ve ever used that I feel comfortable to sleep in any position without fearing leaks.
I have tried three other period panty brands, only to be left feeling like I was wearing a very thick bikini bottom at best, a diaper at worst. This was my first time ordering from Knix. I ordered three different styles and to my shock, I love them all. These boxer briefs feel lightweight, soft and cozy. I wore them overnight on my heaviest day. I had no leaks and they made for a great PJ short. They do have the classic boxer waistband and thicker seams. The seams do show so they will be best worn under thicker or loose fitting clothing or as a cute pajama bottom. A huge thumbs up on these! Thank you Knix!
These are not only the most comfortable undies but the most absorbent and secure period undies I've tried!! Can't wait to buy more!
Love em
Very comfortable and easy washing instructions
| KT Size | Hips | Kids Pant Size | Adult Pant Size |
|---|---|---|---|
| XXS | 25” - 27” | 7 | --- |
| XS | 28” - 30” | 8 - 10 | --- |
| S | 31” - 34” | 12 - 14 | 00 - 2 |
| M | 35” - 38” | 16 - 20 | 4 - 8 |
| L | 39” - 42” | --- | 10 - 14 |
| XL | 43” - 46” | --- | 16 - 18 |
| XXL | 47” - 50” | --- | 20 - 22 |
1. Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.Still Not Sure What Size To Get?
| KT Size | Band | Hips | Kids Pant Size | Adult Pant Size |
|---|---|---|---|---|
| XXS | 23 3/4" - 25 1/4" | 25” - 27” | 7 | --- |
| XS | 25 1/4" - 26 3/4" | 28” - 30” | 8 - 10 | --- |
| S | 26 3/4" - 28 1/4" | 31" - 34" | 12 - 14 | 00 - 2 |
| M | 28 1/4" - 29 3/4" | 35” - 38" | 16 - 20 | 4 - 8 |
| L | 29 3/4" - 31 1/2" | 39” - 42” | --- | 10 - 14 |
| XL | 31 1/2" - 33 1/2" | 43” - 46” | --- | 16 - 18 |
| XXL | 33 1/2" - 35 1/2" | 47” - 50” | --- | 20 - 22 |
1. Band
First, measure around the torso right below the breast
2. Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.
Still Not Sure What Size To Get?
| KT Size | Hips | Kids Pant Size | Adult Pant Size |
|---|---|---|---|
| XXS | 25” - 27” | 7 | --- |
| XS | 28” - 30” | 8 - 10 | --- |
| S | 31” - 34” | 12 - 14 | 00 - 2 |
| M | 35” - 38” | 16 - 20 | 4 - 8 |
| L | 39” - 42” | --- | 10 - 14 |
| XL | 43” - 46” | --- | 16 - 18 |
| XXL | 47” - 50” | --- | 20 - 22 |
1. Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.
Still Not Sure What Size To Get?
| KT Size | Band | Hips |
|---|---|---|
| XS | 28" | 25” - 27” |
| S | 30" | 28” - 30” |
| M | 32" | 31” - 35” |
| L | 34" | 36” - 40” |
| XL | 36" | 41” - 44” |
| XXL | 38" | 45” - 48” |
1. Band
First, measure around the torso right below the breast
2. Hips
KT Leotards are designed to sit on the hips, so measure around the widest part of the hips and refer to the chart above to find the best fit.
Still Not Sure What Size To Get?
| Size | Bust | Hips |
|---|---|---|
| XS | 27” | 25" - 27" |
| S | 30” | 28" - 30" |
| M | 34" | 31" - 35" |
| L | 37” | 36" - 40" |
| XL | 40” | 41" - 44" |
| XXL | 40” | 45" - 48" |
Still Not Sure What Size To Get?
| Size | Hips | Height | Weight |
|---|---|---|---|
| XS/S | 25" - 30" | 4'2" - 5'1" | 65 - 100 lbs |
| M/L | 31" - 40" | 4'9" - 5'6" | 105 - 130 lbs | XL/XXL | 41" - 48" | 4'11" - 5'6" | 135 - 170 lbs |
Still Not Sure What Size To Get?
| KT Size | Hips | Kids Pant Size | Adult Pant Size |
|---|---|---|---|
| XXS | 25” - 27” | 7 | --- |
| XS | 28” - 30” | 8 - 10 | --- |
| S | 31” - 34” | 12 - 14 | 00 - 2 |
| M | 35” - 38” | 16 - 20 | 4 - 8 |
| L | 39” - 42” | --- | 10 - 14 |
| XL | 43” - 46” | --- | 16 - 18 |
| XXL | 47” - 50” | --- | 20 - 22 |
1. Hips
Stand with your feet together and measure around the widest part of your hips and bottom. Keep the measuring tape parallel to the floor.Still Not Sure What Size To Get?
