everyday bikini

Regular price$25

Buy 3+ and save 20%

Leak-Resistant Everyday Bikini Period Underwear

Regular price$25

Buy 3+ and save 20%

Invisible protection for life's little leaks
HSA/FSA Approved

super-light AbsorbencyHolds up to 1 light tampon


HSA/FSA Approved

Free shipping on orders $50+

60 Day Money-Back Guarantee

Absorbent Core

Regular Protection

Machine Washable

The Leak-Resistant Everyday Bikini Period Underwear pairs invisible protection with a classic low-rise cut. The ultra-soft, stretchy fabric hugs the body, while seamless edges minimize panty lines. The absorbent core acts as an alternative to a panty liner, making it perfect for light days (or any time of the month). Where a comfortable, everyday staple meets leak-resistant protection.
  • Light spotting
  • Panty liner alternative
  • Back up a light tampon
  • Discharge
  • Sweat

Outer: 75% Nylon, 25% Spandex
Top Lining: 100% Cotton
Interlining: 95% Cotton, 5% Spandex
Bottom Lining: 100% Polyester


Reusable & Machine Washable:
When you're done wearing, simply wash with cold water and gentle detergent, then hang or lay flat to dry.

Absorbent Zone: Regular
Center lining protection
Multi-layer leak-resistant absorbent core

  • Moisture-wicking top layer
  • Absorbent core
  • Waterproof liner
  • 4-way stretch fabric

Add More Styles To Make A Bundle

Leak-Resistant Period

Everyday Brief


Leak-Resistant Period

High-Rise Smoothing Brief



The bikini undies by Proof feature a mid-rise fit, high cut leg opening, and moderate booty coverage, all in a comfortable stretch fabric that moves with your body.

The bikini features a high-leg opening and narrow sides, with a mid-rise and moderate back coverage. The brief is designed with wider sides, lower rise, and moderate back coverage.

Proof undies are designed to be better for you, and the environment! Single-use plastic period products like tampons and pads end up in landfills and oceans, where they pose a serious threat to wildlife. By switching to Proof, you help to reduce single-use plastic waste.

No you don’t! Our underwear comes in varying absorbencies, ranging from super-light to super-heavy –– holding up to 5 regular tampons or 10 teaspoons. The built-in lining increases in coverage from lightest to heaviest. You can, of course, wear a panty liner with any of our leak-proof underwear, but it is not necessary.

Our leak-proof underwear is super absorbent, moisture-wicking, and comfortable for a wide range of leaks, including periods, bladder leaks, incontinence, after sex, maternity, postpartum, and sweat.

Yes! Our underwear is both moisture wicking and odor resistant to keep you ultra dry and worry-free. Our unique interlock lining wicks away moisture to help keep you feeling dry, and antimicrobial fibers inhibit the growth of bacteria and decrease odor.

Your hip and waist measurements are the most important size when finding the perfect fit. If your measurements fall into different size categories, your hip measurement will be most accurate. Follow our size guide to match your measurements with the right size listed on the chart.

Yes, all our styles of leak-proof underwear are available through 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

Yes, you can absolutely wear our leak-proof undies overnight. They are safer and more comfortable than tampons, pads, and cups.