Astrology Collection Leakproof UltraThin Bikini
Mix & Match: Buy 3+ Save 10%, 6+ Save 20%
Astrology Collection Leakproof UltraThin Bikini
Mix & Match: Buy 3+ Save 10%, 6+ Save 20%
The very latest in leakproof innovation – get more absorbency without any extra bulk! Features an ultra-thin liner that absorbs the same as about 2.5 super tampons, and 360LeakSeal™ technology that locks in leaks at every edge. You get the protection you want from periods and light bladder leaks, so you can feel super comfy and worry-free every single day of the month.
Plus, we've added our logo to the liner, so you can tell the difference between these pairs and our lighter leakproof underwear.
• Classic mid-rise silhouette
• Medium hip & bum coverage
• Ultra-thin, built-in liner
• Absorbs about 2.5 super tampons’ worth of liquid
• Quick dry gusset
• Soft, stretchy PerformaStretch® fabric
• Conforms to your body
The fabric is designed to feel snug at first but relax with wash and wear for a perfect fit.🇺🇸 Free standard shipping over $100*.
Free expedited shipping over $150*. Duty-free. (after discounts, before shipping + taxes)
Within 30 days of delivery, you may exchange for another size, style or store credit. We’re unable to provide refunds on underwear.
Our Absorbency Guide
Your leakproof questions, answered.
Our Leakproof technology features a built-in absorbent liner. Depending on the style you choose, the absorbency can range from about 1-17 tsp of liquid. The result? Confident protection from sweat, discharge, periods, and light bladder leaks.
A gusset is essentially a liner. It’s where you’ll find our leakproof technology. It’s built into the crotch section of the underwear.
Coverage at Knix comes in all shapes and sizes. If we’re talking about silhouettes, we go all the way from thongs to boxers.
We also offer high rise styles, like the Leakproof UltraThin No-Show High Rise, that sits just above the natural waist and gives full coverage through the stomach, hip & bum.
For extra liner coverage, look for undies that have an “extra-long liner” (usually 10”-14”), like in our Dream Short. And our Ultra Zones+ also have full bum coverage, too.
Have a suggested style or coverage? Just let us know. We love the feedback!
Many people refer to them as period underwear or period panties. But leakproof underwear covers you for all of life’s leaks, including periods (even your heaviest flows), sweat, light bladder leaks, postpartum, and discharge.
- Hilary R.Verified Buyer20 minutes agoRated 5 out of 5 starsSuper comfy!
Comfortable and easy to care for.
ComfortRated 5.0 on a scale of 1 to 5Poor ExcellentEffectivenessRated 5.0 on a scale of 1 to 5Poor ExcellentFitRated 0.0 on a scale of minus 2 to 2Runs Small True to Size Runs LargeEase of UseRated 5.0 on a scale of 1 to 5Poor ExcellentWas this helpful? - Becky H.Verified Buyer23 hours agoRated 5 out of 5 starsGreat period undies
Love the period undies for my first few days as a back up to my menstrual cup. They are comfortable to wear and don’t leak
ComfortRated 5.0 on a scale of 1 to 5Poor ExcellentEffectivenessRated 5.0 on a scale of 1 to 5Poor ExcellentFitRated 0.0 on a scale of minus 2 to 2Runs Small True to Size Runs LargeEase of UseRated 5.0 on a scale of 1 to 5Poor ExcellentWas this helpful? - Patricia G.Verified BuyerYesterdayRated 5 out of 5 starsVery Comfortable
Great fit and very comfortable and I love knowing I have the leakproof protection as back up.
ComfortRated 5.0 on a scale of 1 to 5Poor ExcellentEffectivenessRated 5.0 on a scale of 1 to 5Poor ExcellentFitRated 0.0 on a scale of minus 2 to 2Runs Small True to Size Runs LargeEase of UseRated 5.0 on a scale of 1 to 5Poor ExcellentWas this helpful?