Period Swim Bikini Bottom

Period? No problem. These bottoms let you swim with confidence, not discomfort. You can wear them alone or as backup protection to tampons and menstrual cups. Designed with three layers of 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 about the same as 1-3 regular tampons of period blood.

Layer 3: A waterproof outer layer prevents swelling.

Other Features:

- Classic bikini cut

- Bum coverage: Medium

- Super discreet liner

- 50+ UPF protection

- Pair with matching Double Scoop Bikini Top

Finally, a swim bottom you can cannonball in, even on your period.
Image of a chrome heart surrounding text
Image of a absorbancy surrounding text
Absorbs about the same as 1-3 regular tampons of period blood.
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Rapidly absorbs moisture to keep you fresh and dry.
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Thin, subtle, and designed to feel just like regular swimwear.
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Simply machine wash cold and lay flat to dry.

Period? No problem. These bottoms let you swim with confidence, not discomfort. You can wear them alone or as backup protection to tampons and menstrual cups. Designed with three layers of 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 about the same as 1-3 regular tampons of period blood.

Layer 3: A waterproof outer layer prevents swelling.

Other Features:

- Classic bikini cut

- Bum coverage: Medium

- Super discreet liner

- 50+ UPF protection

- Pair with matching Double Scoop Bikini Top

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


Body: 85% Nylon, 15% Spandex

Lining: 85% Nylon, 15% Spandex

Gusset: Fresh Fix Technology®, Polyurethane Film


Additional Product Ingredient Information

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 $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.

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.

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

Yes! All of our regular price swim bottoms and one-pieces are eligible for a return or exchange within 30 days of delivery, as long as the original sanitary strip and tags are attached. Our swim tops are eligible for a return or exchange within 30 days of delivery with original tags attached.

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
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
REUSABLE
COMFORTABLE
JUST PLAIN BETTER
Reviews
average rating 4.3 out of 5
Based on 124 reviews
  • 5 Stars
    93 Reviews
  • 4 Stars
    9 Reviews
  • 3 Stars
    5 Reviews
  • 2 Stars
    6 Reviews
  • 1 Star
    11 Reviews
83% 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
Review posted
Reviewed by Jana D.
Verified Buyer
Period Swim Bikini Bottom
Reviewing
Period Swim Bikini Bottom
Rated 5 out of 5

Cute

Very cute and good quality.

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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 Marie-Christine L.
Verified Buyer
Rated 5 out of 5

Finally a period solution for swimming season!

it's the perfect combo of safety and comfort, I like those

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Reviewed by Chantal P.
Verified Buyer
I'm a...
Parental Figure
I purchased for...
A Teenager/Tween
Band Size
N/A
Pant Size
Kids 12-14
Size Purchased
S
Rated 5 out of 5

Swim bottom

My daughter went to pool parties and camping with confidence this summer! Thank you for making summer periods a non-issue

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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
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Review posted
Reviewed by Elizabeth R.
Verified Buyer
Rated 5 out of 5

Vacation saver!

Purchased these and another style for my teen who was going to get her period during our vacation. Not feeling comfortable with using tampons I went on the hunt for period friendly options. These were a lifesaver for her. She didn't worry about any leaking while swimming. They worked great. I went ahead and ordered her the size according to some other reviews and they fit great. Highly recommend!

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Reviewed by S. H. E.
Verified Buyer
Rated 5 out of 5

Teen daughter approved

Bought for me teen daughter. Went up one size as suggested by reading the reviews. My daughter said it fits perfectly & it was cute (and she's picky). It held up to a day spent swimming & cliff jumping into the water without any leaks.

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