"I've tried a few brands of period undies and these are definitely the best! Absorbent, comfy, what more could you ask for!"
Heavy 
eqv. 4 tampons
Discover our top-selling Boyshorts, the ultimate worry-free and leak-proof solution for periods. Buy a 3-pack and score a free Laundry Bag.
The Scarlet Period Boyshort is a bestseller for a reason. This easy-fitting period underwear, designed in a boyshort style, provides full coverage and protection during your heavier flow days. Wear them like regular underwear, without worrying about leaks, stains, or odours.
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. Read more about cleaning your periodwear.
Pop your used Boyshort in your Laundry Bag and store ready for laundry day.
Made with naturally soft, comfortable, and breathable GOTS Certified Organic Cotton, and featuring a quick-drying built-in absorbent gusset, it can absorb up to 7 teaspoons of fluid (equivalent to roughly 4 regular tampons or 3 regular pads). This makes them ideal for heavy days or overnight wear.
Made from: 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. 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 just a bit less than 1 regular tampon. 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, Bikini Brief in Light or Swim range
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 around 4 regular tampons or 3 pads. It’s our heavy hitter, making them great for full flow days and overnight. 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. Take the time to explore a routine that works for you.
On heavy days, we recommend travelling with a water-resistant travel bag such as the Toiletry Bag, along with a spare pair, so you can change them if needed, pop them straight away and rinse (if you CBF) when you get home.
And if you are feeling Cup curious, you can click to learn more about how Period Cups work. They’re really not as scary as you think!
Nope – who’s that organised? That’s why our Laundry Bag is ace – simply throw your used pair into the bag and store for when you have a full load. Some people like to give them a quick rinse in the shower before popping into the bag, and others don’t. It won’t affect the lifespan of your underwear.
Once you are ready, simply toss them in on a cold wash cycle with mild detergent (no bleach!). DW, your other clothes will be just fine! For drying, you have two options: tumble dry on low or hang them out to dry in the sun.
TIP: 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.
Click to read more about how Period Underwear works.
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, we advise 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 |
