"These seriously feel like real underwear. Super comfy and lightweight. LOVE."
Available in Light and Moderate 
eqv. 2 tampons
Upgrade your period routine with our organic cotton Bikini Brief 3-pack and be rewarded with a handy Laundry Delicates Bag for free!
Designed for ultimate comfort, protection and performance, the Scarlet Period Bikini Brief is the perfect everyday period underwear in a classic mid-rise silhouette. With fast-absorbing 4-layer technology that wicks away moisture, and absorbs and contains fluid to keep you dry during your period, you can bleed, wash and wear on repeat.
In addition to three pairs, this pack also comes with a Laundry Bag to keep your period underwear, activewear, and lingerie safe on laundry day.
Machine washable and reusable, they’re an eco-friendly and cost-effective alternative to disposable pads and tampons. After use, rinse in cold water until it runs clear. Machine wash cold with mild detergent, do not use bleach or fabric softener. Line dry or tumble dry on low.
You can pick your Brief's Absorbency Level:
Light - can absorb 3 teaspoons of fluid (which is roughly equal to 2 regular tampons or 1 regular pad), making them ideal for lighter days, or as back up protection on heavy days.
Moderate - can absorb 5 teaspoons of fluid (which is roughly equal to 3 regular tampons or 2 regular pads), making them ideal for back up protection during your heavier days, or on its own on moderate ones.
95% Organic Cotton, 5% Elastane and a Polyester/Elastane/PUL Quick Dry Gusset. Free from added chemical treatments, including PFAS (independently lab tested).
Harder working than disposable pads and tampons, they last for year not hours.
Did you know more than 12 *billion* pads and 7 *billion* tampons are thrown out every year. The average person with a period uses 11,000 pads, tampons and panty liners in their lifetime. By switching to Scarlet, you're supporting a period and planet positive future.
Scarlet Period Underwear is designed to fit like normal underwear, and feature a multi-layered leak-proof technology that wicks away moisture, absorbs and contains fluid 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.
When it comes to our periods, every flow is different. Heck, every day is different. Which is why we have a range of absorbency levels to suit different needs. Use this as a guide to get the right fit for your flow, so you'll never stress about leaking on the train again.
Super Light: Holds up to 1 teaspoon, which is equal less than 1 regular tampons. Think of it as a new-age panty liner, so it’s great for spotting as well as light leaks and discharge. Try: Invisible Thong
Light: Holds up to 3 teaspoons, which is equal to 2 regular tampons or 1 pad. This is for light days to save you from pesky drips, discharge, and lighter flows. Try: G-String or Bikini Brief in Light
Moderate: Holds up to 5 teaspoons, which is equal to 3 regular tampons or 2 pads. Go for this on your moderate dates, or as extra defence on heavy days with our Period Cup. Try: High-Waisted Brief or Bikini Brief in Moderate
Heavy: Holds up to 7 teaspoons, which is equal to 4 regular tampons or 3 pads. It’s the heavy hitter, making them great to wear on their own, day or night. Try: Boyshort or Period Cup
Depending on the absorbency level you choose and the heaviness of your flow, you can wear our period panties on their own or as backup protection along with a Period Cup or tampon. Take the time to explore a routine that works for you.
After use, rinse them in cold water (we recommend in the shower) until they run clear. Then, machine wash in cold water with mild detergent (no bleach!). Use the Laundry Bag to safeguard them on laundry day. Then just hang out to dry (the sunnier the better) or tumble dry on low - that’s it!
If it’s your first wear, pop them in the washing machine with your next cold cycle - washing them before wearing activates their absorbency even more.
This is a new way to period, and we understand fit may take a couple of goes to get into the swing of things. So, we have a 30-day risk-free trial to support you to find the perfect pair. Basically, if it’s your first time shopping with us and you’re not happy with your product, you may be eligible to claim a refund on that product, even if it’s used. Just email us at support@scarletperiod.com.
We get it — sizing for bottoms is anything but standardised. Which is why this size guide will help break it down for you. For extra ass-urance, make sure to whip out your trusty measuring tape. (Most likely stashed at the bottom of your junk drawer.) Make sure to check both our numeric or letter sizing so no confusion (ie. Our large is a 12). And when in doubt, feedback tells us better to size up.
Still confused? Click for more information on our Returns Policy and our 30-Day Trial Policy. You can also email us at support@scarletperiod.com.
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Measure your waist and hip as per the line to find the right size for you.
| XS | S | M | L | XL | XXL | |
|---|---|---|---|---|---|---|
| AUS | 6 (XS) | 8 (S) | 10 (M) | 12 (L) | 14 (XL) | 16 (XXL) |
| US | 2 | 4 | 6 | 8 | 10 | 12 |
| UK | 6 | 8 | 10 | 12 | 14 | 16 |
| EU | 34 | 36 | 38 | 40 | 42 | 44 |
| Waist | 61 | 66 | 71 | 76 | 81 | 86 |
| Hip | 86-88 | 89-91 | 94-96 | 99-101 | 104-106 | 109-111 |
