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Home / Teen Period Swimwear / Teen Period Swim Bikini Bottom
Best Seller

Teen Period Swim Bikini Bottom

$45.00 USD

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Absorb about 3 regular tampons

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Lower to mid-rise fit

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Medium coverage style

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Premium UPF 50+ fabric

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Machine washable

Rose (she/her) has 35

Rose (she/her) has 35" hips and is wearing a size M

| Black
Rose (she/her) has 35

Rose (she/her) has 35" hips and is wearing a size M

| Black

Rose (she/her) has 35" hips and is wearing a size M

Absorbency: Moderate
Drop
Drop
Drop
Drop
Drop

Color: Black

Size:

True to Size

•

Size:

Size and Fit Guide

Free Shipping on orders $100+

Shipping

Shipping

Processing Timelines

Please allow 1-2 business days for our warehouse team to pack and ship your order. During peak periods such as sales, holidays and product launches, please allow up to 4 business days for us to process your order. Once an order is placed, we cannot guarantee any address updates, order changes or cancellations. Orders placed on Friday after 1PM will not be shipped until the following Monday.


Split Shipments

Most orders will ship from a single warehouse. However, we occasionally ship from a combination of warehouse locations, so you may receive your order in multiple parts. If items from your order ship in separate packages, we’ll send you tracking information for each package when it becomes available.

Delivery Timelines

For the most up-to-date delivery time estimates, please refer to the shipping timeline at checkout. Delivery timelines do not include processing times. See above for details. All transit times are measured in business days which are Monday-Friday, excluding holidays.

Please note, all shipping timelines are estimates and are not guaranteed.

We are not able to ship to US territories (including Puerto Rico, U.S. Virgin Islands, Guam, Northern Mariana Islands and American Samoa) at this time.
Easy Returns within 30 Days

Returns

Returns

Sale & Last Call

Items discounted 30% and below are eligible for size exchange or store credit. Items discounted above 30% and above are final sale – no refunds, store credits, or exchanges can be accommodated.

Free Returns

Knix covers the return shipping fees for exchanges and refunds initiated through our Return & Exchange Portal. Exchange orders initiated through our Return & Exchange portal are also eligible for free shipping within the USA and Canada. Please note, the shipping fees on your original order are non-refundable.

Return Policy

Return policy varies by product, please check if your item is refund or exchange eligible by viewing our full policy here.
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Swim in Style

Classic cut and swim collection staple. Lower to mid-rise with mid-cut leg and medium bum coverage.

Worry-Free Protection

Discreet, built-in protection that absorbs about 3 regular tampons worth.

Sun-Smart Protection

UPF 50+ fabric protects your skin while you soak up the sun.

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Rose (she/her) has 35
| Black
Rose (she/her) has 35
| Black

How to Choose?

Essential

Drop
Drop
Drop
Drop
Drop
  • • Days you don’t need leak protection. Everyday freshness and moisture wicking.
  • tsp
    0 tsp

Heavy

Drop
Drop
Drop
Drop
Drop
  • • Extra peace of mind. For the first days of your cycle, light bladder leaks, or a full night's sleep without a leak.
  • tsp
    about 8-14 tsp
  • pad
    about 1.5-3 regular pads
  • tampon
    about 4-7 super tampons
  • cup
    about 1.5-3 menstrual cups

Light

Drop
Drop
Drop
Drop
Drop
  • • Daily freshness. For sweat, discharge, period spotting, or backup protection.
  • tsp
    about 1-3 tsp
  • pad
    about 1-3 pantyliners
  • tampon
    about 1-3 regular tampons
  • cup
    about 0.5 menstrual cups

Moderate

Drop
Drop
Drop
Drop
Drop
  • • For mid-cycle flow, surprise cough or sneeze leaks, or a really sweaty spin class.
  • tsp
    about 4-8 tsp
  • pad
    about 1-1.5 regular pads
  • tampon
    about 2-4 super tampons
  • cup
    about 0.5-3 menstrual cups

Ultra

Drop
Drop
Drop
Drop
Drop
  • • Ultimate peace of mind. For the heaviest period days, light bladder leaks, unexpected postpartum flow, or overnight protection.
  • tsp
    about 15-20 tsp
  • pad
    about 1.5-2.5 super pads
  • tampon
    about 7-11 super tampons
  • cup
    about 2-3 menstrual cups
LEAKPROOF SWIM WORKS IN LAYERS

Built-in protection that feels like nothing at all.

Looks just like regular swimwear. Non-swelling liner and patented no-show design.

Soft Top Layer

Top Layer

Smooth and comfortable liner in swimsuit fabric.

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Teen Period Swim Sport One-Piece

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Teen First Period Kit - Bikini

From 
$144.00 USD
$192.00
Save $48
4.6
Rated 4.6 out of 5 stars
Based on 118 reviews
Total 5 star reviews: 99 Total 4 star reviews: 8 Total 3 star reviews: 4 Total 2 star reviews: 2 Total 1 star reviews: 5
92%would recommend this product
ComfortRated 4.7 on a scale of 1 to 5
FitRated -0.3 on a scale of minus 2 to 2
EffectivenessRated 4.5 on a scale of 1 to 5
Ease of UseRated 5.0 on a scale of 1 to 5
Write a Review (Opens in a new window)
118 reviews
  • Rated 5 out of 5 stars
    23 hours ago
    Super useful!

    Fits under my daughter’s regular one piece.

    Elizabeth S.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    1 month ago
    Fun in the sun!

    Bought for my daughter. She wore it on a recent trip and didn’t require the leak proof part at the time… but bottoms were so comfortable for her that it didn’t matter. She usually wears S underwear in Knix, but M bathing suit bottoms. S are too snug so suggest sizing up.

    ABel
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    5 months ago
    period swim bottom review

    Fit perfectly and were good for all day use at the beach

    Emily G. G.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    5 months ago
    Best fit ever

    My teen continues to love these swim products! So easy to wash, perfect fit and material.

    Cynthia A.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    5 months ago
    Period Swim bottoms

    The material is excellent and my daughter loves the cut and feel of these SWIM bottoms. She is 13 and wears size Small and it flatters her body. Now she can swim even on those "moon days!" True, it's not perfect because on heavy days some liquid runs down her leg but when that happens she has more reason to jump back in the lake!

    Cheryl A.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    5 months ago
    So comfy

    Best swimwear ever

    Mia F.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    6 months ago
    THANK YOU!

    My 12 year old daughter can now have a "normal" summer. I can't tell you how much of a relief it is to know that she can swim and have fun with her friends at any time of the month.

    Katrin H.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    6 months ago
    This swimwear is a must have for tweens and teens

    My daughter will be 13 yrs old in a couple of months and she just started her period. She’s not ready to try tampons. A friend told us about KT swimwear. I bought her two bottoms (the bikini and the midrise style bottom’s) to try for our Hawaii vacation. She got her period while we were there. She swam in the ocean, pool (went down water slides), snorkeling and bodyboarding. Bottoms stayed in place and provided hours of protection! Going to get her another KT swimsuit for camp. She’s around 92 lbs, wears a size 14 in kids or an XXS/XS (00/0) in adults, purchased a size S in KT and the bottoms fit her perfect.

    Nellie P.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    7 months ago
    5 Stars

    These barhing suit bottoms give my daughter such confidence. She is not missing any water activities this summer!

    Holli
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    7 months ago
    Just what she needed

    Where were these when we were growing up?! Just what my daughter needed with starting right at the beginning of summer time. Made her feel so much comfortable going to the pool and beach for the first time. Thank you!!

    Paige C.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    7 months ago
    Daughter loves them!

    Wish I had bought sooner

    Marie G.
    Verified Buyer
    Was this helpful?
  • Rated 5 out of 5 stars
    9 months ago
    Love these for my teens

    Simple black bottoms avoid any period mishaps. Comfortable, trendy and discreet. Highly recommended.

    Stephanie R.
    Verified Buyer
    Was this helpful?