Sustain Natural ®

Up to 20% Off
Period Underwear

Save on reusable organic cotton period underwear. No one wants to rewear one pair over and over on their period. Since most cycles last longer than a day, we’re giving your wallet (and your washing machine) a break!

What's the deal?


    Use code: 4PAIRS


    Use code: 3PAIRS


    Use code: 2PAIRS


  • "Super Comfy!"

    "I've used Thinx and Dear Kates, and these are so much more comfy! I have a light-medium flow and they held up well without any other product. The elastic in these are top-notch. Definitely keep an eye out for when they have sales!"

    — Cindy

  • "Prefer These Over
    Other Brands!"

    "I love the comfortable cotton and the length of the leak-protection strip, which provides more coverage than another brand I've tried. I wear these as back-up to my cup and highly recommend them."

    — Des

  • Love These!

    "Perfect for lighter days when waiting for your period to fully start/end or as a leak backup. Very brethable so you stay fresh (such a difference from even organic panty liners) and they are not bulky in the slightest. And still organic cotton! Order multiple pairs so that you can wash and wear at the same time!"

    — Emily

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  • How do Sustain Period Underwear work?

    Sustain Organic Cotton Period Underwear are a soft, absorbent, leak-proof alternative to disposable period products. Made with breathable organic cotton, our undies move and feel just like your favorite pair, but have a hidden layer that prevent leaks.

    On their own, Sustain Period Underwear can absorb the equivalent of 1 disposable pad or regular tampon. On heavier days, you can use the undies as a back-up to your tampon or menstrual cup. No more stained jeans or bedsheets!

  • What fabrics are used to make Sustain Period Underwear?

    Sustain Period Underwear are made from 95% organic cotton and 5% spandex, with a hidden leak proof polyurethane laminate lining. The lining is topped with absorbent, 100% organic cotton fleece.

  • How do I wash and care for my Sustain Period Underwear?

    To ensure the longevity of your undies, we recommend that you rinse in cool water after use, machine wash cold, and hang dry. When possible, we also recommend using a laundry bag. Avoid detergents that may contain bleach or fabric softeners.

  • What size should I buy?

    We coordinate our sizing with your hip measurement to give you the comfiest fit possible.

    Wondering how to get your hip measurement? While standing up straight, wrap a soft measuring tape around the biggest part of your hips and booty, then match your measurement to our guide: XS (32-34.5"), S (35-36.5"), M (37-38.5"), L (39-41.5").

Have more questions? We can help!Chat With Us

Period underwear size guide

Size: XS S M L
Hip: 32-34.5 35-36.5 37-38.5 39-41.5

Wondering how to find your hip measurement?

While standing up straight, wrap a soft measuring tape around the biggest part of your hips and booty, then match your measurement to the guide above.

More sizing questions?

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