Flow Stretch

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.