Best Sellers Period Kit

This 5-pair kit includes our top 3 best-selling styles—perfect for teens who want different levels of protection throughout their cycle, from light days to heavy days to everything in-between.


What You Get:
- 2 Light Leakproof No-Show Underwear in Black Each pair absorbs about the same as 1 regular tampon/pantyliners’ worth of blood.
- 2 Super Leakproof™ Underwear in Black Each pair absorbs about 3 super tampons' or 1.5 regular pads' worth of blood.
- 1 Super Leakproof™ Sleepover Short in Black Each pair absorbs about 5.5 super tampons' worth of period blood
- 1 Reusable Pouch in Green or Black*


*In your choice of Bikini or Boyshort.

everything they need for light days, heavy days, and anything in-between.
Image of a absorbancy surrounding text
Period protection for leaks, sweat, and discharge.
Image of a soft surrounding text
Thin, subtle, and designed to feel just like regular underwear.
Image of a moisture fabric surrounding text
Rapidly absorbs moisture to keep you fresh and dry all day.
Image of a overnight protection surrounding text
Sleepover Short features a longer gusset to prevent leaks all night.

This 5-pair kit includes our top 3 best-selling styles—perfect for teens who want different levels of protection throughout their cycle, from light days to heavy days to everything in-between.


What You Get:
- 2 Light Leakproof No-Show Underwear in Black Each pair absorbs about the same as 1 regular tampon/pantyliners’ worth of blood.
- 2 Super Leakproof™ Underwear in Black Each pair absorbs about 3 super tampons' or 1.5 regular pads' worth of blood.
- 1 Super Leakproof™ Sleepover Short in Black Each pair absorbs about 5.5 super tampons' worth of period blood
- 1 Reusable Pouch in Green or Black*


*In your choice of Bikini or Boyshort.

Leakproof Underwear

Main Body: 77% Nylon, 23% LYCRA®

Gusset Liner: 86% Cotton, 10% Spandex, 4% Carbon

Gusset: Fresh Fix Technology®


Machine wash cold with mild detergent, do not bleach, lay flat to dry.


Super Leakproof Underwear

Main Body: 70% Nylon, 30% Spandex 

Lining: 84% Modal, 8% Seaweed, 8% Spandex 

Gusset: Leakproof Technology®, 100% Polyester, PU Film


Machine wash cold with mild detergent, do not bleach, lay flat to dry.


Super Leakproof Sleepover Short

Body: 70% Nylon, 30% Spandex 

Lining: 84% Modal, 8% Seaweed, 8% Spandex 

Gusset: Leakproof Technology®, 100% Polyester, PU Film 


Machine wash cold with mild detergent, do not bleach, lay flat to dry.


Additional Product Ingredient Information

Please note, items that are 35% off or less are eligible for exchange or store credit. All items marked "Black Friday Deals" are final sale.

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.

Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
Image of a chrome heart surrounding text
FOR THIS GENERATION
Image of a chrome heart surrounding text
FOR THE PLANET
Image of a chrome heart surrounding text
FOR REAL LIFE
nothing is tmi here—we promise.
Image of a chrome star surrounding text

Super Absorbency

Absorbs 9–12 tsp (45–60 ml) of blood—that’s about 9–12 regular tampons or pads! Perfect for overnight protection or your heaviest days when changing into a fresh pair might not be convenient.


High Absorbency

Absorbs 4–8 tsp (20–40 ml) of blood, or the equivalent of 4–8 tampons or pads. These are perfect for heavy flow days.


Medium Absorbency

Absorbs up to 3 tsp (15 ml), or about 3 tampons or pads worth of blood. Ideal for light to medium flow days or as backup to tampons or period cups.

All of our period underwear, swimwear, reusable pads, and activewear have our patented leakproof technology built right in.

First Layer: Moisture-wicking, antibacterial technology wicks away sweat and moisture while neutralizing odors to keep you fresh all day long. 

Second Layer: A super thin, highly absorbent liner that holds the power of 3–20 tampons or pads.

Third Layer: A secure, liquid-resistant outer layer keeps leaks from happening.

The short answer: nope! Depending on the absorbency level of your period underwear and the heaviness of your flow, you can wear our period undies on their own or as a backup to tampons or menstrual cups. You can wear our High and Super absorbency underwear alone and be totally protected, while our Medium absorbency underwear can be worn alone on lighter days or as backup on heavier days.

Step 1: Give your underwear a quick rinse under cold water.
Step 2: Throw it in the washing machine with your regular clothes. Wash on cold with mild detergent (no softener or bleach).
Step 3: There are two ways to dry them depending on the undies you have: lay flat to dry for medium absorbency products, or tumble dry on low for high to super absorbency products.
Step 4: That’s it! No ironing needed.

Check out our size chart here. If you want some help, we have virtual fitters ready on deck to help you find your perfect fit. Book a video call with them today.

Because they’re, well, underwear, we can’t accept exchanges or returns on used items. BUT you can try your first pair on your first order risk-free for 30 days!


If you ordered the wrong size of period underwear, we’ll send you a different pair at no cost or offer you a standard refund within 30 days of delivery (excluding original shipping fees).


If your order included multiple period underwear, open, wash, and wear one pair only. That way if you don’t love them, any unopened packages from the same purchase will be eligible for an exchange or standard refund (excluding original shipping fees).


All unopened packages will be donated to local organizations to support people in need.


*All Mystery Bundles are final sale.

Image of a chrome heart surrounding text
COMFORTABLE
Image of a chrome heart surrounding text
ABSORBENT
Image of a chrome heart surrounding text
JUST PLAIN BETTER
Image of a chrome heart surrounding text
REUSABLE
Image of a chrome heart surrounding text
COMFORTABLE
Image of a chrome heart surrounding text
ABSORBENT
Image of a chrome heart surrounding text
JUST PLAIN BETTER
Image of a chrome heart surrounding text
REUSABLE
Image of a chrome heart surrounding text
COMFORTABLE
Image of a chrome heart surrounding text
ABSORBENT
Image of a chrome heart surrounding text
JUST PLAIN BETTER
Image of a chrome heart surrounding text
REUSABLE
Image of a chrome heart surrounding text
COMFORTABLE
Image of a chrome heart surrounding text
ABSORBENT
Image of a chrome heart surrounding text
JUST PLAIN BETTER
Image of a chrome heart surrounding text
REUSABLE
Image of a chrome heart surrounding text
COMFORTABLE
Image of a chrome heart surrounding text
ABSORBENT
Image of a chrome heart surrounding text
JUST PLAIN BETTER
Image of a chrome heart surrounding text
REUSABLE
Image of a chrome heart surrounding text
COMFORTABLE
Image of a chrome heart surrounding text
ABSORBENT
Image of a chrome heart surrounding text
JUST PLAIN BETTER
Image of a chrome heart surrounding text
REUSABLE
Image of a chrome heart surrounding text
COMFORTABLE
Image of a chrome heart surrounding text
ABSORBENT
Image of a chrome heart surrounding text
JUST PLAIN BETTER
Image of a chrome heart surrounding text
REUSABLE
Image of a chrome heart surrounding text
COMFORTABLE
Image of a chrome heart surrounding text
ABSORBENT
Image of a chrome heart surrounding text
JUST PLAIN BETTER
Image of a chrome heart surrounding text
REUSABLE
Reviews
average rating 4.9 out of 5
Based on 291 reviews
  • 5 Stars
    267 Reviews
  • 4 Stars
    24 Reviews
  • 3 Stars
    0 Reviews
  • 2 Stars
    0 Reviews
  • 1 Star
    0 Reviews
100% of reviewers would recommend this product to a friend
Review posted
Reviewed by Sandra B.
Verified Buyer
(closed) Period Kit
Reviewing
(closed) Period Kit
I'm a...
Parental Figure
I purchased for...
A Teenager/Tween
Pant Size
Teen 12-16
Size Purchased
M
Usage
  • Back-up Protection
  • Primary Protection
  • Period
Rated 5 out of 5

Amazing first kit

My daughter loved this kit. She got her period and was ready because she had these to start off with!!

Loading...
I recommend this product
Quality
Rated 5 out of 5
Comfort
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
Effectiveness
Rated 5 out of 5
Was this helpful?
Review posted
Reviewed by Tanya
Verified Reviewer
I'm a...
Adult
I purchased for...
Myself
Pant Size
Teen 18-20
Size Purchased
XL
Usage
  • Back-up Protection
  • Primary Protection
  • Period
Rated 5 out of 5

Amazing product

I wish I had of discovered these a long time ago. I have never had a leak when wearing these even on my heaviest days

Loading...
I recommend this product
Quality
Rated 5 out of 5
Comfort
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
Effectiveness
Rated 5 out of 5
Was this helpful?
Review posted
Reviewed by Amelia
Verified Reviewer
I'm a...
Adult
I purchased for...
Myself
Pant Size
Teen 00-2
Size Purchased
M
Usage
  • Primary Protection
  • Period
Rated 5 out of 5

Great starter set!

These underwear are so comfortable I will wear the oh no underwear on non-period days.

This is helpful to try out the different types and figure out what you might add- depending if this is your primary or just a back up. If you choose to use it as primary consider getting two sets! Or be okay doing a wash on day 3 to make it through.

Loading...
I recommend this product
Quality
Rated 5 out of 5
Comfort
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
Effectiveness
Rated 5 out of 5
Was this helpful?
Review posted
Reviewed by PC
Verified Buyer
(closed) Period Kit
Reviewing
(closed) Period Kit
Rated 5 out of 5

Worked great for my teen

No leaks!

Loading...
I recommend this product
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
Was this helpful?
Review posted
Reviewed by Angie
Verified Buyer
(closed) Period Kit
Reviewing
(closed) Period Kit
Rated 5 out of 5

Handy to have for that first time

It was a few months until my 12-year old actually needed this, but I was glad to have it for her first period. She liked being able to try out the different types, and we just ordered more of the ones she preferred.

Loading...
I recommend this product
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
Was this helpful?