Black Friday 2025

This style runs true to size. Order your most standard size. 

You can see our size chart here.

Our Fabrics

Main: Flow Stretch™ 95% Nylon with 5% Spandex Knit

Lining: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 88% Polyester with 12% Nylon 

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse any fresh blood off in the sink or the shower.

Hang to dry then add to your laundry pile. 

Machine wash warm, no bleach.

Tumble dry low. Do not dry clean or iron. 

Each pair of Period. underwear can hold up to 2 tampons worth of blood.

Check out our absorbency test video here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from a blade of grass: Hi! You might notice me. I am one of a trillion trillion blades of grass. But I notice you. With just one pair of Period underwear, you're saving the Earth from so much non-disposable junk. I have some blade of grass friends who live near landfills and let me tell you, slow decomposing tampons and pads are not pretty. Next time you see a breeze going through a field of grass, know that it's us waving hello and thank you at you.

This style runs true to size. Order your most standard size. 

You can see our size chart here.

Our Fabrics

Main: Flow Stretch™ 95% Nylon with 5% Spandex Knit

Lining: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 88% Polyester with 12% Nylon 

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse any fresh blood off in the sink or the shower.

Hang to dry then add to your laundry pile. 

Machine wash warm, no bleach.

Tumble dry low. Do not dry clean or iron. 

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from a blade of grass: Hi! You might notice me. I am one of a trillion trillion blades of grass. But I notice you. With just one pair of Period underwear, you're saving the Earth from so much non-disposable junk. I have some blade of grass friends who live near landfills and let me tell you, slow decomposing tampons and pads are not pretty. Next time you see a breeze going through a field of grass, know that it's us waving hello and thank you at you.

This style runs true to size. Order your most standard size. 

You can see our size chart here.

Our Fabrics

Main: Flow Stretch™ 95% Nylon with 5% Spandex Knit

Lining: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 88% Polyester with 12% Nylon 

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse any fresh blood off in the sink or the shower.

Hang to dry then add to your laundry pile. 

Machine wash warm, no bleach.

Tumble dry low. Do not dry clean or iron. 

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from a blade of grass: Hi! You might notice me. I am one of a trillion trillion blades of grass. But I notice you. With just one pair of Period underwear, you're saving the Earth from so much non-disposable junk. I have some blade of grass friends who live near landfills and let me tell you, slow decomposing tampons and pads are not pretty. Next time you see a breeze going through a field of grass, know that it's us waving hello and thank you at you.

This style is intended for teenagers or petite adults and runs true to size. 

Teens should order their most standard size. 

A petite women's extra small can comfortably fit in a teen medium.

A petite women's small can comfortably fit in a teen large.

You can see our size chart here.

Our Fabrics

Main: PeriodTech™ 85% Nylon with 15% Spandex Knit

Lining: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse for a few seconds.

Either hand wash and hang dry, or add to the laundry pile.

Regular wash, no bleach.

Tumble dry low or hang dry.

Do not dry clean.

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

You can see the length of the absorbent panel here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from a Cheetah: Hi! You know me. You know how much I love to run. Running is the best thing in the universe. The only that ruins it is when you run past a decomposing tampon or pad. Man, that sucks. There are some things you can't unsee and that's one of them. But not for much longer! With incredible people like you, we're going to end all this ridiculous waste and make my runs fantastic again. Kudos.

This style runs true to size. Order your most standard size. 

You can see our size chart here.

Our Fabrics

Body: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse for a few seconds.

Either hand wash and hang dry, or add to the laundry pile.

Regular wash, no bleach.

Tumble dry low or hang dry.

Do not dry clean.

None, zero, nada, zilch. We are proud to be one of the few period underwear brands that do not use any toxins in our products because who wants chemicals near the most sensitive part of their body? Not us. Or you.

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

You can see the length of the absorbent panel here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from a Coral Reef: Hi! Thank you for using non disposable products. It may feel like a small gesture - but it’s not. I’m sick of getting tampons and pads getting caught up in my beautiful branches and you’re helping to keep that trash out of my home. Just one pair of Period means that 5 pads/9 tampons are never used or thrown away. Thank you! Next time you swim by me, stop and say hi. 

This style runs true to size. Order your most standard size. 

You can see our size chart here.

Our Fabrics

Body: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse for a few seconds.

Either hand wash and hang dry, or add to the laundry pile.

Regular wash, no bleach.

Tumble dry low or hang dry.

Do not dry clean.

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

You can see the length of the absorbent panel here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from an Octopus: Hi. I wanted to send you a personal message of gratitude for being conscious enough to stop using disposable products. Imagine me now, shaking your hand eight times. That’s what I’m doing. And sending you good energy with my two hearts. Tampons and pads take generations to biodegrade, cause endless pollution and they are frankly stupid inventions - and I should know what stupid is because I have eight brains. Be proud of yourself - you’re making a big change. 

This style fits like a true bike short.

You can see our size chart here.

Our Fabrics

Body: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse any fresh blood off in the sink or the shower.

Hang to dry then add to your laundry pile. 

Machine wash warm, no bleach.

Tumble dry low. Do not dry clean or iron. 

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from a used tampon: Hi, I’m a tampon that was last used in 1946 - only once - and I’m still languishing on a land fill. As you can imagine, I’ve had a lot of time to reflect. What was the point of me? Why did someone use me once for just a few hours and nearly a hundred years later, I’m still here? Why? This feels like a pretty stupid system to me. Please overthrow it! Please use non-disposable products so that no tampon ever has to feel this useless again. Thank you. 

This style fits like a true boxer brief, if you want a more relaxed fit, we recommend sizing up!

You can see our size chart here.

Our Fabrics

Body: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse for a few seconds.

Either hand wash and hang dry, or add to the laundry pile.

Regular wash, no bleach.

Tumble dry low or hang dry.

Do not dry clean.

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

You can see the length of the absorbent panel here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from a frog: you’re doing it, you’re saving the world from waste, and more than that, embracing a new way of thinking when it comes to periods. I am in awe. Enjoy the boxer! 

This style runs true to size. Order your most standard size. 

You can see our size chart here.

You can see the length of the absorbent panel here.

Our Fabrics

Body: 95% Cotton with 5% Spandex Jersey

Absorbent Layer: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse for a few seconds.

Either hand wash and hang dry, or add to the laundry pile.

Regular wash, no bleach.

Tumble dry low or hang dry.

Do not dry clean.

Each pair of Medium Flow Period. underwear can hold up to 4 tampons worth of blood.

Check out our absorbency test video here.

You can see the length of the absorbent panel here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from a Star Fish: I wanted to tell you that on this rare instance, I’m not the star. You are. By wearing just one pair of Period, you’ve saved the world from 4 tampons that will take generations to decompose and let’s not get into pads. Thank you from the bottom of the ocean.

This style is intended for postpartum use and is very supportive in the lower abdomen area. if you want a more relaxed fit, we recommend sizing up. 

You can see our size chart here.

Our Fabrics

Body: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse any fresh blood off in the sink or the shower.

Hang to dry then add to your laundry pile. 

Machine wash warm, no bleach.

Tumble dry low. Do not dry clean or iron. 

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from a Coral Reef: Hi! Thank you for using non disposable products. It may feel like a small gesture - but it’s not. I’m sick of getting tampons and pads getting caught up in my beautiful branches and you’re helping to keep that trash out of my home. Just one pair of Period means that 5 pads/9 tampons are never used or thrown away. Thank you! Next time you swim by me, stop and say hi. 

This style is one size fits all. 

Our Fabrics

Body: 95% Organic Cotton with 5% Spandex Jersey

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse any fresh blood off in the sink or the shower.

Hang to dry then add to your laundry pile. 

Machine wash warm, no bleach.

Tumble dry low. Do not dry clean or iron. 

Each pantyliner can hold 1-2 tampons, worth of blood.

Check out our absorbency test video here.

How long will one pantyliner last?

Panty liners are the mildest of absorbers. If it’s the last days of your period or everyday discharge or a sneeze-worth of a small bladder leak, one reusable panty liner will last all day just like a disposable panty liner. If you’re using it for heavier period days or medium bladder leaks, you might need to change every few hours. It takes a day or two of getting used to, but when to change will soon become natural intuition. If you do leak at first, please forgive us - just this once. Remember how many tampons you have forgiven. Instead, treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long a panty liner will last for you. Also remember, if you have problems, questions or just want to have a chat about panty liners email us at hello@period.co. 

Personal message from the entire ecosystem: thank you for using non-disposable products, it’s this kind of thinking that’s going to help save The Planet. Thank goodness, you came along.

This style is one size fits all. 

Our Fabrics

Body: 95% Organic Cotton with 5% Spandex Jersey

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse any fresh blood off in the sink or the shower.

Hang to dry then add to your laundry pile. 

Machine wash warm, no bleach.

Tumble dry low. Do not dry clean or iron. 

Each pad can hold up to 9 tampons, worth of blood.

Check out our absorbency test video here.

How long will one pad last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Personal message from the entire ecosystem: thank you for using non-disposable products, it’s this kind of thinking that’s going to help save The Planet. Thank goodness, you came along.

This style runs true to size. Please order your most standard size.

You can see our size chart here.

Our Fabrics

Body: 94% Polyester Brushed Microfiber with 6% Spandex Jersey

Lining: 95% organic cotton, 5% spandex

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse any fresh blood off in the sink or the shower.

Hang to dry then add to your laundry pile. 

Machine wash warm, no bleach.

Tumble dry low. Do not dry clean or iron. 

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Personal message from soil: I know it’s highly unusual to get a message from soil but in this case, I just had to say thank you. Just by using one pair of Period underwear, you’re saving the natural world from 9 tampons or 4 pads being thrown away and (because they don’t biodegrade) polluting the Earth for generations. From me and all my microbes - thank you. 

This style is intended for teenagers or petite adults and runs true to size. 

Teens should order their most standard size. 

A petite women's extra small can comfortably fit in a teen medium.

A petite women's small can comfortably fit in a teen large.

You can see our size chart here.

Our Fabrics

Body: 94% Nylon Brushed Microfiber with 6% Spandex Jersey

Lining: 95% organic cotton, 5% spandex

Absorbent Layer: 100% Polyester  

Leak Resistant Layer: 100% Polyester PUL

How to take care of your Period.

Rinse any fresh blood off in the sink or the shower.

Hang to dry then add to your laundry pile. 

Machine wash warm, no bleach.

Tumble dry low. Do not dry clean or iron. 

Each pair of Period. underwear can hold up to 9 tampons worth of blood.

Check out our absorbency test video here.

How long will one pair of Period. last?

Everybody periods differently so it’s tough to be exact. Our average time is about 8 hours on a heavier flow day. Though some customers need to change after 3 to 4 hours, and others can go up to 14 hours (lucky them!). As your period gets lighter, one pair can take you through the day and night (just like regular underwear). But again, everybody Periods differently, so you need to take one cycle to figure out exactly how often you need to change. Start with a conservative estimate on your heavy days, and check in on your Period underwear after 4 hours. If you still feel good, give it another hour. Keep going until you figure out your limit. Here at Period, we find we need between 3 to 4 pairs on the first two heavy days, including evenings. And if you leak, please forgive us! Just this once. (Remember how many tampons you have forgiven). Treat the ‘leak’ as a gift and note the hour of your leakage. That is the best indicator of your ‘flow threshold’ how long the underwear will last for you.

Message from an Oak Tree: Hellooo. I’m a 100 year old oak tree. I live near a landfill and 80 years ago, I saw a tampon get thrown away. Guess what? It’s still there! Still decomposing! I can’t believe it. All the pads and tampons that people have thrown away are all there. And it’s so gross! I used to look out at fields and meadows and woodland. And now I just see decomposing bad products that will taken another hundred years to degrade. I have to confess, I started to lose a little faith in humans. Then you came along. Just by wearing one pair of Period just once, you’ve stopped 2 pads or 4 tampons from being in my eye line. Thank you!