Period Swim Freestyle One-Piece

Tuck Dives. Cannonballs. Lazy rivers. This leakproof swimsuit works as hard as they do. Both sporty and cute, it not only stops leaks, but fits like a glove, and offers a comfier, greater range of motion.


On light days, they can wear it alone. On heavy days, they can use it as backup with a tampon or menstrual cup.

Key features:

- Feels just like regular swimwear

- Bum coverage: Medium

- Thin & undetectable period-absorbing gusset

- Anti-slip racerback straps for added mobility

- No shelf bra or padded cups for reduced drag

- 50+ UPF protection

- Fully lined

Sleek, supportive, leak-fighting protection—all in one-piece.
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Holds about 3 regular pads’ worth of blood
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Designed by the former Canadian Olympic Apparel Designer
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Thin, discreet, and feels just like regular swimwear
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No bra pads for a smoother, closer fit

Tuck Dives. Cannonballs. Lazy rivers. This leakproof swimsuit works as hard as they do. Both sporty and cute, it not only stops leaks, but fits like a glove, and offers a comfier, greater range of motion.


On light days, they can wear it alone. On heavy days, they can use it as backup with a tampon or menstrual cup.

Key features:

- Feels just like regular swimwear

- Bum coverage: Medium

- Thin & undetectable period-absorbing gusset

- Anti-slip racerback straps for added mobility

- No shelf bra or padded cups for reduced drag

- 50+ UPF protection

- Fully lined

Body: 85% Nylon, 15% Spandex

Lining: 85% Nylon, 15% Spandex

Gusset: Leakproof Technology®, PU Film 


Machine wash cold with mild detergent, do not bleach, 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 3.9 out of 5
Based on 48 reviews
  • 5 Stars
    27 Reviews
  • 4 Stars
    5 Reviews
  • 3 Stars
    7 Reviews
  • 2 Stars
    4 Reviews
  • 1 Star
    5 Reviews
71% of reviewers would recommend this product to a friend
Quality
Rated 3 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 Stephanie T.
Verified Buyer
Period Swim Freestyle One-Piece
Reviewing
Period Swim Freestyle One-Piece
Height
<5’5”
Size Purchased - Knixteen Underwear
L
Rated 5 out of 5

Great teen swim

My daughter loves her swimsuit. We purchased, she wore it 3 times, left for 2 weeks summer camp and got it stolen. She was so bummed and disappointed, it was really the only thing that made her feel confident enough to swim during her periods. We then had to purchase a second one. But it is worth every penny.

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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 Andrea M.
Verified Buyer
Period Swim Freestyle One-Piece
Reviewing
Period Swim Freestyle One-Piece
Band Size
28"
Pant Size
Teen 12-16
Size Purchased
M
Usage
  • Pool
  • Sun Bathing
Rated 5 out of 5

Fits well

Fits very well and works great!

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I recommend this product
Quality
Rated 5 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
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Review posted
Reviewed by Tia T.
Verified Buyer
Period Swim Freestyle One-Piece
Reviewing
Period Swim Freestyle One-Piece
I'm a...
Adult
I purchased for...
A Teenager/Tween
Current Band Size
36
Pant Size
Teen 18-20
Size Purchased
L
Usage
  • Swim Class
Rated 5 out of 5

One piece period wear

Effective, comfortable, affordable and durable

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I recommend this product
Quality
Rated 4 out of 5
Comfort
Rated 5 out of 5
Effectiveness
Rated 5 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
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Review posted
Reviewed by Leanne Y.
Verified Buyer
Period Swim Freestyle One-Piece
Reviewing
Period Swim Freestyle One-Piece
Band Size
34"
Pant Size
Teen 4-10
Size Purchased
M
Usage
  • Pool
  • Swim Class
Rated 5 out of 5

Perfect for my active teen!

My daughter wanted a suit for swim team. This one works great for practice or meets when on her period.

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I recommend this product
Quality
Rated 5 out of 5
Comfort
Rated 5 out of 5
Effectiveness
Rated 5 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
Was this helpful?
Review posted
Reviewed by Tsugumi K.
Verified Buyer
Period Swim Freestyle One-Piece
Reviewing
Period Swim Freestyle One-Piece
I'm a...
Adult
I purchased for...
Myself
Pant Size
Teen 4-10
Size Purchased
M
Band Size
N/A
Rated 5 out of 5

Fit small

I got this for myself. I feel it fit smaller than other style but still like it.

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I recommend this product
Quality
Rated 5 out of 5
Comfort
Rated 4 out of 5
Sizing
Rated -1 on a scale of minus 2 to 2, where minus 2 is Fits Small, 0 is True to SIze and 2 is Fits Large
Effectiveness
Rated 3 out of 5
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