Leakproof Bikini Period Underwear

Regular price$39

Buy 3+ and save 20%

Leakproof Bikini Period Underwear

Regular price$39

Buy 3+ and save 20%

Basic made better, protection from all kinds of leaks
HSA/FSA Approved

heavy AbsorbencyHolds up to 4 regular tampons


HSA/FSA Approved

Free shipping on orders $50+

60 Day Money-Back Guarantee

Absorbent Core

Extended Protection

Machine Washable

Our Leakproof Bikini Period Underwear is a classic style in a mid-rise fit and features a high leg opening. With extended leak protection perfect for heavy flows, this style gives you peace of mind from day to night. Sleep a little more soundly tonight because this style works to keep you protected overnight on your period (no more stained sheets!). Crafted with our patented Leak-Loc® absorbent core technology that helps you feel dry and confident.
  • Heavy periods
  • Moderate bladder leaks
  • Pad alternative
  • Alternative/back up a tampon or cup
  • Discharge
  • Sweat
  • Fights odor
  • Overnight protection

Outer: 75% Nylon, 25% Spandex
Body Lining: 100% Cotton
Top Lining: 100% Polyester
Interlining: 69% Cotton, 25% Polyester, 6% Acrylate
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: Extended 
Front-to-back lining protection
Additional waterproof layer for maximum protection
Multi-layer leakproof absorbent core
Leak-Loc® bonded edge technology

  • Front-to-back lining protection
  • Moisture-wicking top layer
  • Absorbent core
  • Waterproof liner
  • Waterproof outer fabric

Add More Styles To Make A Bundle

Leakproof Period

Mesh Hipster


Leakproof Period

Essential High-Rise 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.

The leakproof bikini by Proof is perfect for heavy periods. It holds up to 4 regular tampons - that’s 8 tsp! - of liquid, making it perfect for all-day or overnight wear. The bikini is also equipped with front-to-back leakproof protection for extended 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.