Rated 4.7 out of 5
Based on 41 reviews
Leakproof Hipster Underwear
$43
Holds up to 5 Regular Tampons or 10 Teaspoons

The ultimate in leak protection


Rated 4.6 out of 5
Based on 26 reviews
Leakproof Brief
$35
Holds up to 3 Regular Tampons or 6 Teaspoons

A classic silhouette with discreet leak protection


Rated 5.0 out of 5
Based on 39 reviews
Leakproof Thong
$25
Holds up to 1 Regular Tampon or 2 Teaspoons

Eliminate panty lines and light leaks


Rated 4.7 out of 5
Based on 26 reviews
Leakproof Bikini Underwear
$39
Holds up to 4 Regular Tampons or 8 Teaspoons

Basic made better, protection from all kinds of leaks


Rated 4.8 out of 5
Based on 19 reviews
Mesh Hipster Leakproof Underwear
$39
Holds up to 4 Regular Tampons or 8 Teaspoons

Super absorbent and powerful leak protection


Rated 4.9 out of 5
Based on 24 reviews
Leakproof Lace Cheeky
$37
Holds up to 3 Regular Tampons or 6 Teaspoons

Cheeky style with built-in leak protection


Rated 4.9 out of 5
Based on 9 reviews
Leak-resistant High Waisted Smoothing Brief
$29
Holds up to 1 Light Tampon or Panty Liner

A leak-resistant undie that smooths and soothes with light compression in all the right places.


Rated 4.4 out of 5
Based on 18 reviews
Leakproof High Waisted Brief
$39
Holds up to 3 Regular Tampons or 6 Teaspoons

Fully covered, fully comfortable.


Rated 5.0 out of 5
Based on 4 reviews
Leak-resistant Everyday Bikini
$25
Holds up to 1 Light Tampon or Panty Liner

Invisible protection for life's little leaks


Rated 5.0 out of 5
Based on 8 reviews
Leak Proof® Lace Back Bikini
$43
Holds up to 3 Regular Tampons or 6 Teaspoons

A little extra beauty for your booty


Rated 4.9 out of 5
Based on 13 reviews
Leak Proof® High Waisted Lace Brief
$49
Holds up to 3 Regular Tampons or 6 Teaspoons

Vintage style with powerful protection


Plus Size Underwear in Sizes Up to 3XL

Proof offers plus size period underwear in the following measurements:

XL — US size 16–18 with 44–47" hips and 34–37" waist
2XL — US size 20–22 with 47–50" hips and 37–40" waist
3XL — US size 24–26 with 50–54" hips and 40–44" waist

Plus Size Underwear — Protection for All Types of Leaks

Our plus size period underwear isn’t just for periods. Protect yourself against all types of leaks:

- Period
- Bladder
- Sweat
- Maternity
- Postpartum
- Workout

Protection for All Flow Types

Whether you’re looking for heavy flow plus size period panties or super light protection for barely there days, Proof offers several levels of absorbency.

- Super-Light: Up to 1 light tampon or panty liner
- Light: Up to 1 regular tampon or 2 teaspoons of liquid
- Moderate: Up to 3 regular tampons or 6 teaspoons of liquid
- Heavy: Up to 4 regular tampons or 8 teaspoons of liquid
- Super-Heavy: Up to 5 regular tampons or 10 teaspoons of liquid

Top FAQs

see all FAQS

What styles of plus size leak proof underwear does Proof offer?

Currently, you can shop up to 3XL in our Leakproof Brief, Leakproof Hipster Underwear, Leak-resistant Everyday Undie, and Leak-resistant Everyday Bikini.

In the future, we hope to offer plus size period panties in all of our styles.

Do I need to wear a tampon or pad with plus size period undies?

Our plus size period panties are leak-resistant or leakproof (depending on the absorbency level), so you won’t need to pair them with any other period products unless you want to.

Is Proof plus size period underwear moisture wicking and sweat resistant?

Yes! Our patented absorbent core makes all of our plus size period underwear super moisture-wicking and sweat resistant so you stay feeling dry all day long.

How comfortable are the plus size period undies?

Unlike other bulky brands, Proof plus size period panties look and feel just like your favorite underwear, with discreet, trustworthy built-in protection. Our undies are silky soft, breathable, and made with move-with-you material. Plus, they come in a variety of styles and silhouettes, so you can choose the style most comfortable for you.

How do I wash Proof plus size underwear?

We recommend hand rinsing your plus size period underwear before tossing them in the washing machine on a delicate cycle. Always use mild detergents and wash in cold water to preserve the life of your period panties. Hang or lay flat to dry, and give them up to 24 hours to fully dry depending on absorbency.

Can I wear Proof plus size leak proof undies every day?

You can wear plus size period panties every day of the week as long as you have enough to go around! Even if you’re not on your period, our light and super-light absorbency panties are perfect for everyday discharge, bladder leaks, sweat, and anything else that might get in the way.

What is the best plus size period underwear?

Proof offers some of the best period underwear for plus sizes on the market because of our patented Leak-Loc® technology. These panties are comfortable, breathable, moisture-wicking, and offer serious protection you can count on.

How Proof Plus Size Undies Work?

All of our plus size period underwear is made with several layers of materials in order to provide all-day protection. The layer closest to your skin wicks away moisture so you feel dry, followed by a layer of absorbent antimicrobial fibers that fight bacteria and odors and a layer that acts as a liner shield to keep leaks at bay. The outermost layer is made from water-proof fabric and Leak-Loc® edges, to guarantee coverage and protection.

Go with your flow

We've designed period underwear for every phase of your flow, from surprise light spotting in-between periods to super heavy periods and beyond.