Period Swim Full-Coverage Bikini Bottom

More comfortable with more coverage? We made these just for you. A mid-rise fit with fuller bum coverage than our regular bikini bottoms, and the leak-fighting power of about the same as 2-3 super tampons! Perfect for beach days, pool parties and all the hangouts you would’ve missed.

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 2-3 super tampons.

Layer 3: A waterproof outer layer never swells.

Other Features:

- Bum coverage: Full

- Fully lined

- Super-discreet liner

- 50+ UPF protection

- Pair with matching Double Scoop Bikini Top

Feel full of confidence in full-coverage swimwear.
Image of a absorbancy surrounding text
Absorbs about the same as 2-3 super tampons of period blood.
Image of a moisture fabric surrounding text
Rapidly absorbs moisture to keep you fresh and dry.
Image of a light and comfy surrounding text
Thin, subtle, and designed to feel just like regular swimwear.
Image of a machine washable surrounding text
Simply machine wash cold and lay flat to dry.

More comfortable with more coverage? We made these just for you. A mid-rise fit with fuller bum coverage than our regular bikini bottoms, and the leak-fighting power of about the same as 2-3 super tampons! Perfect for beach days, pool parties and all the hangouts you would’ve missed.

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 2-3 super tampons.

Layer 3: A waterproof outer layer never swells.

Other Features:

- Bum coverage: Full

- Fully lined

- Super-discreet liner

- 50+ UPF protection

- Pair with matching Double Scoop Bikini Top

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 4.5 out of 5
Based on 76 reviews
  • 5 Stars
    57 Reviews
  • 4 Stars
    10 Reviews
  • 3 Stars
    1 Review
  • 2 Stars
    4 Reviews
  • 1 Star
    4 Reviews
88% 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 Melissa Q.
Verified Buyer
Period Swim Full-Coverage Bikini Bottom
Reviewing
Period Swim Full-Coverage Bikini Bottom
Height
5’6 – 5’8”
Usual Pant Size - Knixteen
Womens 4-8
Size Purchased - Knixteen Underwear
M
Rated 5 out of 5

Great style for my teen!

This is the perfect addition to our summer activities. It pairs well with all of her bathing suit tops, has a very absorbent pad and covers well!

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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 Rita L.
Verified Buyer
Period Swim Full-Coverage Bikini Bottom
Reviewing
Period Swim Full-Coverage Bikini Bottom
I'm a...
Adult
I purchased for...
A Teenager/Tween
Current Band Size
28
Pant Size
Teen 00-2
Size Purchased
S
Usage
  • Pool
Rated 5 out of 5

Swim /bottoms

Swim bottoms fit great and worked well for my 12 year old daughter

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I recommend this product
Quality
Rated 5 out of 5
Comfort
Rated 5 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 Michelle
Period Swim Full-Coverage Bikini Bottom
Reviewing
Period Swim Full-Coverage Bikini Bottom
Rated 5 out of 5

5 Stars

Perfect fit and amazing customer service. They went above and beyond to help me with an order issue. Will be a repeat customer.

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Reviewed by Holly S.
Verified Buyer
Period Swim Full-Coverage Bikini Bottom
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Period Swim Full-Coverage Bikini Bottom
Rated 5 out of 5

Great product for teen girl!

These bottoms were comfortable and made well. My daughter loves them!

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I recommend this product
Comfort
Rated 5 out of 5
Fit
Rated -2 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 Renee D.
Verified Buyer
Period Swim Full-Coverage Bikini Bottom
Reviewing
Period Swim Full-Coverage Bikini Bottom
Rated 5 out of 5

Excellent period brief

I bought these for my nearly 13 year old daughter. Purchased size medium and they fit perfectly. She is a women's size small or 4. She is a competitive swimmer and she wears the brief under her full race suit. This style has good coverage in the back and didn't bunch or ride. A great option for young swimmers!

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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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