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Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch
Scarlet Invisible Period Thong – Super Light, Discreet & Comfortable Protection
Scarlet Invisible Period Thong – Super Light, Discreet & Comfortable Protection
Scarlet Invisible Period Thong – Super Light, Discreet & Comfortable Protection
Scarlet Invisible Period Thong – Super Light, Discreet & Comfortable Protection
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch
Scarlet Invisible Period Thong – Super Light, Discreet & Comfortable Protection
Scarlet Invisible Period Thong – Super Light, Discreet & Comfortable Protection
Scarlet Invisible Period Thong – Super Light, Discreet & Comfortable Protection
Scarlet Invisible Period Thong – Super Light, Discreet & Comfortable Protection
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch

Period Invisible Thong

Ultra-light. Barely there. Zero lines.

$20.00

Barely there, quietly working. For spotting, sweat and just-in-case days, under one tampon's worth. The pair you wear when you're not sure you need one, and are glad you did.

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Australian designed · PFAS-free · 30-Day Risk-Free Trial

    Ultra-light, barely-there comfort
    Machine Washable
    Chemical-free (no PFAS!)
    1% for the Planet

✨ Invisible & Comfortable: Seamless design for a smooth, discreet fit.

✨ Light but Mighty: Perfect for spotting, sweat and discharge.

✨ Breathable Fabric: Soft, breathable polyamide & elastane blend for comfort.

✨ Chemical-Free: No harmful chemicals, including PFAS - independently lab-tested.

✨ Rinse in Cold Water: After wearing, rinse in cold water until it runs clear to keep them fresh.

✨ Machine Wash Cold: Toss them in with mild detergent (no bleach or fabric softener, please).

✨ Dry with Ease: Line dry or tumble on low - no need for extra care.

✨ Need more info? Please read our complete guide to caring for your period underwear here.

✨ Made with 76% Polyamide and 24% Elastane for a soft, breathable feel with perfect stretch.

✨ Quick-drying, leak-proof gusset made from polyester/PUL, keeping you dry and fresh all day.

✨ Free from harmful chemicals like PFAS - independently lab tested for your peace of mind.

✨ Fit Note: Our underwear runs on the slightly smaller side - if you're between sizes, size up.

✨ Teen-to-Adult Fit: Our sizing is unique - please refer to both the numerical (e.g. 10, 12) and letter sizing (e.g. M, L) in our guide.

✨ Australian Sizing: We use AU sizes - international customers, check our Size Guide.

✨ Still Unsure? Contact us for advice. We love a chat!

Did you know that over 12 billion pads and 7 billion tampons end up in landfills yearly? By choosing Scarlet, you're supporting a more sustainable future - where self-care and sustainability go hand in hand.

✨ High-Quality, Safe Fabrics: Made with care, free from PFAS and harmful chemicals, and independently lab-tested for your safety.

✨ Eco-Conscious Manufacturing: Crafted with a focus on quality and reducing environmental impact.

✨ Recyclable Packaging: Minimal waste for a cleaner world.

✨ 1% for the Planet: Scarlet is proud to contribute to environmental stewardship with every purchase.

Size Chart

Size chart for Period Invisible Thong
Scarlet Period Invisible Thong | Like a panty liner, PFAS-free, Soft with 360° stretch

Period Invisible Thong

$20.00
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Scarlet Period Invisible Thong | 3-Pack

Made for days when you think your period is over

You can still feel sexy on your period. Our Invisible Thong proves it.

A barely-there style for light flows and spotting, under one tampon's worth. Feels like you're wearing nothing.

  • 360-degree stretch, no visible lines
  • PFAS-free and lab tested
  • Under one tampon's worth
  • A new-age panty liner for sweat and drips
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Your Questions, Answered

How do they work?

Scarlet Period Underwear is designed to fit like normal underwear and features multi-layered leak-proof technology that wicks away moisture, absorbs fluid, and contains it to keep you dry and protected. 

The built-in leak-proof technology is harder working than disposable pads which means it can safely hold more liquid and last for years not hours. Loved by all; you can read some reviews.

Do I need to wear a cup, tampon, or pad too?

Depending on the absorbency you choose and the heaviness of your flow, you can wear our period undies on their own or as backup along with a Period Cup or tampon.

What does the absorbency level mean?

Super Light: Holds up to 1 teaspoon, equal to less than one regular tampon. Think of it as a new-age panty liner, great for spotting, light leaks and discharge. Try: Invisible Thong

Light: Holds up to 3 teaspoons, equal to 2 regular tampons or one pad. For light days, drips and discharge. Try: G-String or Bikini Brief in Light-Moderate

Moderate: Holds up to 5 teaspoons, equal to 3 regular tampons or 2 pads. For moderate days, or as extra defence on heavy days with our Period Cup. Try: High-Waist Brief or Bikini Brief in Moderate-Heavy

Heavy: Holds up to 7 teaspoons, equal to 4 regular tampons or 3 pads. Our heavy hitters are great worn on their own, day or night. Try: Boyshort or Period Cup

What is your 30-day risk-free trial?

We offer a 30-Day Risk-Free Trial for first-time shoppers for one pair of underwear. If you’re unsatisfied or have sizing concerns, email us at support@scarletperiod.com.

How do I pick the right size for me?

We get it, sizing for bottoms is anything but standardised. Which is why this size guide will help break it down for you. Make sure to check both our numeric and letter sizing so no confusion (ie. our large is a 12).

When in doubt, feedback tells us better to size up. Still confused? You can also email us for help at support@scarletperiod.com.

Why buy a bundle?

Save money and stay prepared! With your period lasting between 3-8 days, a multipack ensures you have enough pairs to manage your cycle comfortably. Check out some of our best-selling sets.
★★★★★

"This Aussie-based label is putting the cool into period knickers."

Refinery29

★★★★★

"A surefire way to make mindful, sustainable choices that are good for you and the world you live in."

STYLE magazine

★★★★★

"Scarlet takes the cake for the coolest period underwear brand."

LifeHacker

Real advice for real cycle days