Unders by Proof

We believe that quality period and leak care should be accessible to all women. That's why we created Unders: affordable, machine washable period and leakproof underwear that looks as good as it feels. Designed by and for women with Proof's unique patented Leak-Loc™ technology and now available at Target.


Holds up to 1 light tampon

• Leak resistant up to 1 light tampon

• Panty Liner Replacement

• Everyday Protection

• Light Spotting

• Discharge


Holds up to 2 regular tampons

• Leakproof up to 2 tampons

• Moderate Periods

• Replace a Pad

• Replace or Backup a Tampon/Cup

• Fights Odor

• Wicks Moisture


Holds up to 4 regular tampons

• Leakproof up to 4 tampons

• Heavy Periods

• Replace a Pad

• Replace or Backup a Tampon/Cup

• Fights Odor

• Wicks Moisture

You can buy Unders at some of your favorite retailers in-store.

To find Unders in a store near you, use our store locator tool.

Unders undies feature strong protection, but should be washed gently. Simply toss in the washing machine on a delicate cycle, using cold water and mild detergents. Hang or lay flat to dry.

To learn more about how to care for your pair, keep reading.

Unders is designed in a range of absorbencies to fit every flow. To find the perfect protection, select a pair based on your absorbency needs.

-Light: Holds one light tampon or panty liner. Great for in-between days, light flows, spotting, and back up protection.
-Regular: Holds up to 2 tampons. Great for moderate flows, replacing pads, and replacing or backing up tampons and cups.
-Heavy: Holds up to 4 tampons. Great for heavy flows, replacing pads, tampons, and cups, and for overnight protection.

Yes! Unders is perfect back up for tampons and cups, or to replace your current period products all together. Have an unpredictable flow? Wear Unders every day for built-in protection on in-between days.