Period Swim Board Shorts

Our most-requested swim style ever! Perfect for teens who want fuller coverage in the front and back, while being fully protected on their period. Wear it alone on light days, with a tampon or menstrual cup on heavy days or whatever works for your flow.

Other Features:
- Bum coverage: Max
- Wide waistband for comfort
- Mesh interior lining
- Super discreet liner

Pair with matching Double Scoop Bikini Top

Shorts that have you covered. Literally.
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Absorbs the equivalent of about 2-3 super tampons worth of blood
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Thin, subtle, and designed to feel just like regular swimwear, in or out of the pool
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Simply machine wash cold and lay flat to dry

Our most-requested swim style ever! Perfect for teens who want fuller coverage in the front and back, while being fully protected on their period. Wear it alone on light days, with a tampon or menstrual cup on heavy days or whatever works for your flow.

Other Features:
- Bum coverage: Max
- Wide waistband for comfort
- Mesh interior lining
- Super discreet liner

Pair with matching Double Scoop Bikini Top

MAIN BODY: 90% POLYESTER, 10% SPANDEX

MESH BRIEF: 86% NYLON, 14% SPANDEX

GUSSET LINING:  85% NYLON, 15% SPANDEX

GUSSET INTERIOR: FRESH FIX TECHNOLOGY®, 100% PU FILM


MACHINE WASH COLD, DO NOT BLEACH, DO NOT IRON, DO NOT DRY CLEAN, LAY FLAT TO DRY

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.


We offer free standard shipping on all orders over $80.

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. 

Canadian Orders: Please allow 2–4 business days for shipping to the GTA, 3–10 business days for urban areas, and 6–15 business days for remote locations.

NOTE: Orders placed on Friday after 1 PM will not be processed until the following Monday.

 FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
FOR THIS GENERATION
FOR THE PLANET
FOR REAL LIFE
nothing is TMI here—we promise.
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Our period swim bottoms contain a triple-layer gusset that absorbs your flow and locks in leaks, whether you're in or out of the water. When they go in the wash with detergent, the blood releases through the top layer—leaving your swimwear fresh and clean for next time. Yes, your other clothes will remain stain-free!

Here's the breakdown of our 3-layer leakproof technology:

Layer 1: A silky-smooth top layer that sits comfortably against the skin.

Layer 2: A highly-absorbent middle layer designed with our leakproof technology to absorb up to 1-3 tampons worth of period blood.

Layer 3: A waterproof outer layer prevents swelling. 

Not always. When your flow is light, our swimwear can be worn alone without any additional period protection. On super heavy days, we recommend wearing a tampon or menstrual cup with your swimwear. Every period is different though, and we recommend doing whatever makes you feel most confident.

Machine wash cold and lay flat to dry. Do not bleach, iron, or dry clean.

Check out our size chart here.

Absolutely! The leakproof liner built into all of our period swimwear is undetectable, so they look and feel just like regular swimwear.

Our styles are made to fit teen bodies. For period swimwear in adult sizes, please visit Knix.

 COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
ABSORBENT
JUST PLAIN BETTER
REUSABLE
Reviews
average rating 4.4 out of 5
Based on 19 reviews
  • 5 Stars
    12 Reviews
  • 4 Stars
    4 Reviews
  • 3 Stars
    2 Reviews
  • 2 Stars
    0 Reviews
  • 1 Star
    1 Review
89% of reviewers would recommend this product to a friend
Quality
Rated 4 out of 5
Comfort
Rated 4 out of 5
Effectiveness
Rated 4 out of 5
Sizing
Rated 0 on a scale of minus 2 to 2, where minus 2 is Fits Small, 0 is True to Size and 2 is Fits Large
Write a Review
Review posted
Reviewed by Robyn W.
Verified Buyer
Height
5’6 – 5’8”
Size Purchased - Knixteen Underwear
M
Rated 5 out of 5

Perfect for water activities

Perfect for being active outside and doing water activities. Fit well, even on an adult. Slightly lower rise.

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I recommend this product
Comfort
Rated 4 out of 5
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
Effectiveness
Rated 4 out of 5
Ease of Use
Rated 5 out of 5
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Review posted
Reviewed by Jennifer H.
Verified Buyer
Height
5’6 – 5’8”
Usual Pant Size - Knixteen
Womens 10-14
Size Purchased - Knixteen Underwear
L
Rated 5 out of 5

My teen loves these!

We’ve bought these every year as she’s grown. She loves them and feels confident to swim every day of the month. I highly recommend!!

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I recommend this product
Comfort
Rated 5 out of 5
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
Effectiveness
Rated 5 out of 5
Ease of Use
Rated 5 out of 5
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Review posted
Reviewed by Tanya
Verified Buyer
Rated 5 out of 5

Perfect

Seeing as these are not offered in the womens line I took a chance an ordered. I'm 46 yrs old and wanted something more then a bikini bottom or cycling short for aquafit. I normally wear between a med/large and played it safe and ordered the xl. Now they do fit a little big but thankfully can tighten with the waist string and I only wear these on my light days cause I'm a little too self conscious on heavier days. But I absolutely love these shorts and wish they were around when I was a teen.

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Reviewed by Breanne De J.
Verified Buyer
Rated 5 out of 5

Teen swim shorts review

My dtr really enjoys her swim shorts. They give her confidence when swimming and have been very helpful this summer!

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Review posted
Reviewed by Jennifer J.
Verified Buyer
Rated 5 out of 5

Swim board Shorts

My daughter loves there and they fit pretty good. She didn't seem to leak. Hard to gauge what size to get in these

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