Woman wearing and adjusting the elastic band on blue PFAS-free period underwear in bathroom.
March 27, 2024

A Deep Dive into PFAS-Free Period Underwear and 11 Promising Brands

Pinterest Icon.Instagram icon

he cyclical shedding of the uterine lining is a burden at least half of the world’s population has to endure and yet for so long, periods and period products have been shrouded in shame and mystery. Well, no more. We’re here to take a proper deep dive into one of menstrual care’s biggest game-changers: period underwear.

Sold as a safer, more eco-friendly, and more comfortable way to bleed, period underwear has gone from a niche product to something you can pick up at Walmart. But not all period underwear is made equal. Shockingly, some have even been found to contain PFAS – damaging chemicals that may be risking reproductive health.

We believe that making better choices for the planet should go hand in hand with making better choices for your own body and well-being. That’s why we’ve put together a list of the best PFAS-free period underwear and answered all the questions you might have on what PFAS are and why switching to period underwear can be so impactful.

As it turns out, keeping your flow in check need not come at the risk of your health, or the planet’s.

Table of  Contents

What Is Period Underwear?

Period underwear are underpants that are designed to absorb menstrual blood either as a way to replace things like tampons and pads or to work alongside them for extra security. They usually have moisture-wicking fabric that helps keep you dry and comfortable throughout your flow, but different period underwear options will operate slightly differently.

Why Should You Try Period Underwear?

A woman wearing orange period underwear with her hands on her belly in a heart sign.

Purely in terms of period care, here are some of the benefits that period underwear can offer:

  • Extra comfort: Many people find regular period support uncomfortable with some even experiencing pelvic pain from things like tampons or cups. Period underwear done well can be super comfortable and supportive, even during your worst cramps.
  • No worry about toxic shock syndrome: Unlike tampons, which can’t be used for too long without risking infection, period underwear is completely safe.
  • Easier to wear when active: Hate having to change pads or tampons between activities or how bulky your pads look under leggings? Period underwear has none of those problems. It’s often far more seamless looking, and more comfortable to wear when active.
  • Saves money: Feminine hygiene products are notoriously pricy with many states and countries even taxing these basic items. Great period underwear helps ensure that you’re not constantly having to buy fresh packs of pads etc. and should allow you to save money in the long term.

Why Choose PFAS-Free Period Underwear?

At the start of 2023, Thinx, a major period underwear brand, settled a 3-year class action lawsuit regarding PFAS that had been found in its underwear. A year later, the company has laid off 95 people. Thinx and the lawsuit they faced have created a massive shift in the period care industry and for good reason.

Sometimes referred to as “forever chemicals”, PFAS have been found in just about everything – from shampoo to non-stick pans. They’re also often used to make fabrics more water resistant, hence why they sometimes appear in period underwear. The reason they shouldn’t be anywhere near our crotches, or anywhere else for that matter, is down to the carcinogenic risk associated with certain PFAS substances as well as their hormone-disrupting abilities. They’ve been linked to period irregularities, polycystic ovarian syndrome, and other ovarian-related issues. 

The scary thing is that because these chemicals aren’t biodegradable, they tend to collect in our bodies and water systems when we wash PFAS-containing items. That’s why they’re a personal health issue as well as an environmental one. They’ve been known to accumulate in fish and other wildlife with research indicating that they may be harming the health of dolphins, sea otters, and even remote arctic polar bears.

Choosing PFAS-free period underwear is an important way to protect your own health and do better for the planet at the same time. We can’t destroy or remove existing PFAS in our environment, but we can limit how much more is added.

The History and Environmental Impact of Period Care Products

Sanitary pads, panty liners and tampons and their plastic packaging displayed on a pink surface.

Unfortunately, period care products negatively impacting the environment isn’t a new occurrence. Non-recyclable and non-biodegradable menstrual products have been an issue for decades with things like sanitary pads and tampons continuously adding to global waste and pollution issues. Many traditional period products contain microplastics and chemicals such as synthetic fragrances, parabens, etc. which further exacerbate how much they add to environmental problems.

We can’t judge ourselves, or anyone else who has used these products though. Most of us did so unknowingly or in desperation to maintain some level of hygiene and comfort in a world that is decidedly unfriendly to people with periods. For as long as women have bled, so too have we been trying to find ways to do so without giving up our freedom. In ancient Greece, lint was wrapped around wood as a make-shift tampon and in her book on moss, ecologist Robin Wall Kimmerer talks about Native women who used dried moss to soak up their flow.

With period cups, tampons, and pads, we’ve come a long way in terms of convenience, but it may be costing our health and the health of our environment.

How Is PFAS-Free Period Underwear Eco-Friendly?

Period underwear is fundamentally more eco-friendly than traditional menstrual products like tampons and pads because of how much less waste it creates. PFAS-free underwear takes that one step further by also reducing the amount of harmful toxins that you and our planet are being exposed to every time your cycle comes around.

Where Can You Buy PFAS Free Period Underwear?

PFAS-free period underwear is far more widely available than many realize. Target and Walmart both stock some of the best PFAS-free period underwear brands and every one of the products we’ll mention later in this article are easily available to order online.

How do you Care for Your PFAS Free Period Underwear?

Most period underwear brands will provide wash instructions specific to their products, but in general, here’s how to best care for your PFAS-free period underwear:

  • Wash on a cold wash/delicate setting.
  • Use a mild detergent.

That’s it! It shouldn’t be that much different from taking care of any of your other underwear. Some take things a step further by soaking their period underwear in a water and vinegar mixture before putting them in the washing machine, but that’s a personal preference. Revol Cares also suggests using a bit of dish soap on your underwear before it goes in the wash to help break down blood.

How Often Should You Replace Your Period Underwear?

Most period underwear is designed to be worn for about 10-12 hours and in terms of long-term use, should last from 2-4 years, depending on how frequently they’re washed and used.

Is PFAS-Free Period Underwear Worth the Cost?

As this Glamour UK article explains, you generally need about three pairs of period underwear in rotation and while it can be a bigger expense upfront than pads or tampons, " it does work out cheaper in the long run.” At $5 a pack, you could spend at least $60 a year just on tampons whereas three pairs of Period Company underwear will clock you in at about $36 and see you through at least 2 years of periods.

Not only that, but PFAS-free period underwear gives you greater peace of mind in terms of health and your impact on the planet. They may be an investment, but we think the cost pays off ten-fold.

Period Underwear vs. Other Period Care Options

A cartoon illustration of various period care options with smiley faces dancing including sanitary pad, tampon, menstrual cup, and period panty.

Period underwear tends to be more comfortable, more cost-effective, and more convenient than most traditional period care options but what about the less traditional ones? 

One of the other eco-friendly period products many turn to is the menstrual cup. While these are certainly less wasteful than tampons or pads, cups can sometimes be difficult to insert and clean whereas period underwear is always low-effort. We also enjoy that, unlike most period cups, period underwear is often plastic-free.

That said, when it comes to managing your flow, you have to do what suits your lifestyle and needs. Women and people with periods have enough to deal with as it is without worrying about people judging their menstrual choices.

11 of Our Favorite PFAs-free Period Brands

Here it is, the ultimate list of leak-proof, super comfy, and totally PFAS-free period underwear:

1. Revol Cares

This brand started as a homegrown effort to counteract the worst parts of having a heavy flow and is now making some of the best PFAS-free period underwear out there.

Most Popular Style: The brand’s bestseller is the Charlie, a cozy mid to high-rise boxer short designed to sleep or lounge in. They’re full coverage and extra stretchy for maximum comfort.

Material: A mix of bamboo, organic cotton, and spandex. Naturally anti-microbial.

Fit Options: Boxer shorts, thongs, and high-rise briefs.

The Flow Q: Light to very heavy flow (lab-tested).

Sizes: XS-7XL

Price Range: $33-$55

Sustainability Stats:

  • Uses organic and plant-based materials.
  • Tested by Mamavation to be PFAS-free.
  • Low-waste and responsible production.

2. Aisle

Period Aisle is one of those brands that are always innovating the concept of non-toxic period underwear, like introducing period boxers to better cater to their trans-masc. customers. One of the coolest features many of the styles include is a “booster” or reusable pad that, as this reviewer explains, can be used to boost the absorbency of the underwear for heavier days.

Most Popular Style: The classic black brief is a favorite for a reason. Not only does it hold 8+ tampons worth of blood when used with a booster, but it’s also full coverage for extra comfort.

Material: Tencel, Lyocell, organic cotton, recycled polyester, and spandex.

Fit Options: Briefs, bikinis, thongs, and boxers.

The Flow Q: Light to very heavy.

Sizes: XS-5X

Price Range: $24-$52

Sustainability Stats:

  • Certified B Corp.
  • Various charitable initiatives.
  • Uses organic and plant-based materials.

3. Period Company

The Period Company is keeping things simple and sustainable with a limited but highly effective selection of PFAS-free period underwear. We love how classic, comfortable, and chic their products are.

Most Popular Style: These super-absorbent high-waisted briefs are the brand’s star product and were described by NYMag as being “super comfortable” and leak-proof. 

Material: Organic cotton, spandex, and polyester.

Fit Options: Boxers, bikinis, sleep shorts, and high-waisted briefs.

The Flow Q: Light to very heavy.

Sizes: XS-6X

Price Range: $12-$22

Sustainability Stats:

  • Main fabric is organic cotton.
  • Various charitable initiatives.

4. TomboyX

This brand was founded more than 10 years ago with the dream of providing better underwear options for queer folks. Today, they’re one of the most inclusive menstrual care brands out there and continue to push for more gender-affirming products for all.

Most Popular Style: The First Line Leakproof 4.5" Trunks are TomboyX’s bestseller with the standout feature being the soft waistband that keeps them in place all day.

Material: Spandex, polyester, and OEKO-TEX Certified cotton.

Fit Options: Trunks, briefs, boxers, boyshorts, and bikinis.

The Flow Q: Light to heavy.

Sizes: 3XS-6X

Price Range: $20-$32

Sustainability Stats:

  • Certified B Corp.
  • Uses OEKO-TEX Certified cotton.

5. Rif Care

This 100% BIPOC and women-owned business is on a mission to create menstrual products with fewer harmful chemicals in them, and a whole lot more love. 

Most Popular Style: The small brand only stocks one style – but we love the comfortable, mid-rise fit on this leak-proof underwear and the mesh panels that add extra detail. Just because it’s meant to be worn on your period, doesn’t mean the underwear can’t be cute.

Material:  Regenerative hemp, organic cotton, Tencel, spandex, and recycled polyester.

Fit Options: Mid-rise brief.

The Flow Q: Light to moderate.

Sizes: XS-3X

Price Range: $29

Sustainability Stats:

  • Uses organic and plant-based fibers.
  • Donates 2% of all sales to women through programs that support and uplift victims of family violence, and sexual assault.

6. ModiBodi

ModiBodi is making some of the best period underwear without chemicals. We love how many styles and colors they offer and the fact that they’ve managed to create a range of period underwear that is 97% biodegradable!

Most Popular Style: The Sensual Hi Waist Bikini is one of the brand’s biggest sellers. Not only is it built for heavy, overnight flows, but it features a lace detail around the waistband that is as pretty as it is comfortable.

Material: Bamboo viscose, merino wool, elastane, and polyester.

Fit Options: Boy shorts, bikinis, thongs, and briefs.

The Flow Q: Light to very heavy.

Sizes: XS-6XL

Price Range: $28-$50

Sustainability Stats:

  • Biodegradable and sustainably sourced fabrics.
  • Certified B Corp.
  • Carbon emission transparency.
  • Charitable donations.


This brand has won various awards for their PFAS-free period underwear and with a name that stands for “wake up, kick ass” that makes sense. Multiple women trialed their products for Refinery29 and raved about the comfort and sense of security they provided as well as the lack of any visible panty lines.

Most Popular Style: The WUKA Ultimate™ Midi Brief (Heavy) has 213 five-star reviews on their site. Not only are they super comfortable but they’ll keep you dry even on your heaviest day.

Material: TENCEL Modal (climate neutral), elastane, and polyester.

Fit Options: Briefs, bikinis, thongs, and boxer shorts.

The Flow Q: Light to very heavy.

Sizes: XXS-6XL

Price Range: $20-$40

Sustainability Stats:

  • Sustainable fabrics eg. climate neutral Tencel, organic cotton, etc.
  • Certified B Corp.
  • Plastic-free packaging.

8. Saalt

Saalt is a PFAS-free period underwear brand working hard to break taboos around menstruation and make the experience more comfortable for all. We love the variety of colors and styles they stock – there’s something for everyone!

Most Popular Style: One of the top sellers of the brand is their Leakproof Comfort Boyshort (Heavy) – a style that according to a featured customer review from one Jessica J, is comfortable enough to wear every day. 

Material: Tencel modal, organic cotton, polyester, and elastane.

Fit Options: Sleep shorts, briefs (mid and high-rise), boyshorts, and thongs.

The Flow Q: Light to very heavy.

Sizes: XXS-2XL

Price Range: $27-$45

Sustainability Stats:

  • Various charitable donations.
  • Uses sustainable and organic fabrics.
  • Certified B. Corp.
  • Certified plastic negative.

9. Cora

This brand has a no-fuss, no-frills approach to period care. Just simple, great products that work so that you don’t have to stress about your flow.

Most Popular Style: The Free-To-Flow Period Underwear can hold up to 3 regular tampons worth of liquid so you can rest assured there’ll be no accidents when wearing them. They’re also super soft and breathable.

Material: Cotton, elastane, and polyester.

Fit Options: Brief and sleep shorts.

The Flow Q: Light to very heavy.

Sizes: XS-XXL

Price Range: $30-$38

Sustainability Stats:

  • Certified B. Corp.
  • Donates menstrual products to those in need for every purchase.

10. Dear Kate

Dear Kate’s big claim to fame is making “the most breathable period undies” on the market thanks to their plastic-free fabric. We love the more playful touches on their designs. There are definitely a few pairs that would cheer you up even on the most hormonal days …

Most Popular Style: USA Today named the brand’s Ada Thong the very best period thong on the market. Though only for lighter flows or the very last days of your flow, the comfort and style of this product have earned it many fans.

Material: Nylon, LYCRA, polyester, and elastane.

Fit Options: Hipsters, briefs, and thongs.

The Flow Q: Light to very heavy.

Sizes: XS-3X

Price Range: $28-$48

Sustainability Stats:

  • Donates to the Center for Safety & Change

11. Lilova

From swimwear to teen support and post-partum, Lilova is making PFAS-free period underwear for all stages.

Most Popular Style: The Jade Cotton Brief’s classic style has made it a firm favorite of the brand. It’s highly absorbent (4 regular tampons worth!) and has full coverage so you can rest assured there’ll be no leaking.

Material: Organic cotton, elastane, microfiber, and breathable TPU.

Fit Options: Thongs, bikinis, boyshorts, and briefs

The Flow Q: Light to very heavy.

Sizes: XS-3X

Price Range: $16-$36

Sustainability Stats:

  • Uses organic cotton and OEKO-TEX 100 Certified fabrics.

Putting the Period on PFAS

Periods are tough enough as it is without bringing hazardous chemicals into the mix. Choosing PFAS-free period underwear is a way to keep your body safer and choosing period underwear at all is a way to keep the planet a little cleaner. Not only that but period underwear saves you money, discomfort, and hassle. You’re already having to deal with all those hormones – why not keep your period support as simple and clean as possible?

FAQs About PFAS Underwear

Woman wearing PFAS- Free period panties holding a post it with a question mark in front to represent questions about the underwear.

What period underwear is PFAS-free?

Thankfully, many period underwear options are PFAS-free. Some of our favorites include Rif Care, Tomboy X, and WUKA. They’re all size and flow-inclusive brands trying to make period care safer and more comfortable.

Has Thinx removed PFAS?

It’s tricky to know whether Thinx has removed PFAS from their products if only because the brand maintains that PFAS aren’t part of their product design and that “they don’t treat their finished products with PFAS”. This is despite a lawsuit that painted a different picture. At this point, we’d simply recommend skipping the brand altogether.

Is Knix free of PFAS?

Knix products should be free of PFAS as they don’t intentionally use the chemicals in their production and also employ third-party testing to check for contamination.

Does Ruby Love have PFAS?

No, Ruby Love does not have PFAS in any of their period products.

Does Victoria’s Secret use PFAS?

No, Victoria’s Secret does not use PFAS chemicals in the manufacturing of their period products.

Do all period pants have PFAS?

We’re happy to say that not all period pants of PFAS chemicals in them. Many brands, like Saalt and Bambody, have taken active steps to ensure that their period underwear is free of these substances and safe for use. We hope to see more brands follow suit and hope that third-party testing for hazardous chemicals in period products one day becomes the norm so that can all feel safer.