14 Best Non-Toxic Period Underwear Free of PFAS, Tested

This is my full review of the best non-toxic period underwear without PFAS or other harmful chemicals in 2025. I’ve been wearing organic period underwear for over 7 years now. At first, it was all about reducing waste. The average person uses 11,000+ disposable menstrual products in their lifetime, which is insane! I personally bought, tested, and reviewed 15+ non-toxic period undies while living my everyday active lifestyle—at the gym, in aerial classes, and even on 8-hour hikes. I read lab reports, contacted brands, and wore each pair through real flows and real-life demands. Jump to the list>

Some failed miserably—I’m talking leaks within an hour, chafing seams, and “leakproof” claims that didn’t stand a chance on a heavy day. But others surprised me—in a good way. I’ve found certified PFAS-free period underwear that kept me dry and comfortable for over 9 hours, even on my busiest days.

These are the only non-toxic period panties that passed every single test!

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How We Tested These Period Panties

When it comes to period underwear, the bar is high. I wore these non-toxic period panties during the lightest days and through heavy flows. I tested them at the gym, during aerial classes, and even on an 8-hour hike through the Grand Canyon. I’ve moved, stretched, sweated, and sat for hours in them.

Here’s how I narrowed down the best non-toxic period underwear for 2025:

• PFAS-Free Verification: We only considered brands that provide third-party lab testing or a clear brand statement confirming their underwear is PFAS-free. Some brands even provided full lab reports showing undetectable levels of fluorine—a strong indicator of toxic-free period panties.
• Non-Toxic & Natural Materials: Only non-toxic period products made from safe, skin-friendly fabrics made the cut. Think organic cotton period underwear, TENCEL™, or OEKO-TEX® certified blends. 
• Ethical Manufacturing: Transparency matters. Brands with clear commitments to fair labor practices and eco-conscious production stood out. We looked at where and how the period panties were made, ensuring the safest products also aligned with sustainable and ethical values.
• Comfort + Leak Protection: We put each pair through real-life challenges—workouts, travel, long days, and heavy periods. If it couldn’t keep up, it didn’t make the list. The best period underwear should feel like a second skin, not a bulky pad. They should also stay dry and breathable—even on day two.
• Size Inclusivity: Bodies come in all shapes. We prioritized PFAS-free period underwear brands offering inclusive sizing (from teens to plus size) because safe, chemical-free period underwear should be accessible to everyone—not just those who fit a narrow size chart.

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What Is Period Underwear?

Period underwear is reusable underwear designed to absorb menstrual blood, offering an alternative to disposable pads and tampons. These undies have built-in absorbent layers that trap fluid, wick away moisture, and help prevent leaks, without the bulk of a pad or the discomfort of a tampon.

Unlike traditional underwear, period underwear typically includes a combination of absorbent, antimicrobial, and leak-resistant fabrics sewn directly into the crotch area. Depending on the brand and design, they can hold anywhere from 1 to 5 tampons’ worth of blood. Most are machine-washable, making them both low-maintenance and eco-friendly.

Although the idea of reusable period products isn’t new (think cloth rags and sponges used for centuries), modern period underwear entered the market around 2014, when brands like Dear Kate began reimagining period care. Today, the global market for period underwear is expected to exceed $800 million by 2029.

Compared to disposable pads and tampons, non-toxic period underwear is significantly more sustainable, since it produces no landfill waste or plastic packaging. It’s also gentler on the skin, making it a great choice for those sensitive to synthetic materials or adhesives. Many users find it more discreet, with no rustling, shifting, or visible strings. And because it’s washable and reusable, it can save money over time—especially for those with heavier or longer periods.

Who Should Consider Using Organic Period Underwear?

Period underwear can work for just about anyone, but they’re especially popular with:

• Teens – comfortable, easy to use, and non-invasive
• Postpartum parents – great for light bladder leaks and irregular postpartum bleeding
• Travelers and commuters – ideal for long days without bathroom access
• Eco-conscious users – reducing disposable waste
• People with sensory sensitivities – no adhesive, string, or rustling

Whether used alone or as a backup for a cup or tampon, period underwear offers a flexible, fuss-free way to manage your cycle—and with non-toxic options now available, it’s safer than ever.

Related Post: Best Non Toxic Feminine Washes

Types of Period Underwear 

Of course, period underwear isn’t one-size-fits-all—both in design and absorbency. Today’s options are tailored to suit everybody, flow, and personal preferences, making them a versatile addition to your menstrual routine.

Absorbency Levels

Most brands categorize their non-toxic period underwear by how much fluid they can hold, often measured in tampons’ worth or milliliters:

• Light flow (1–2 tampons’ worth): Ideal for spotting, the beginning or end of your cycle, or as backup for a cup or tampon.
• Medium flow (2–3 tampons’ worth): Great for daytime use or moderate bleeding.
• Heavy flow (4–5 tampons’ worth or more): Designed for overnights, postpartum, or heavy bleed days.
• Super/overnight: Some brands offer ultra-absorbent versions that can replace a pad or tampon entirely, even on the heaviest days.

It’s important to match the absorbency level with your cycle day. Too little and you risk leaks; too much and it might feel bulky or less breathable.

Styles and Fits

Just like regular underwear, period underwear comes in a variety of cuts to match your comfort and outfit needs:

• Thongs: Best for very light spotting or as a backup—minimal coverage, minimal absorbency.
• Bikini & Hipster: A go-to everyday option with moderate coverage and comfort.
• Boyshorts: Offer extra coverage and are great for lounging, sleeping, or heavier flows.
• High-waisted: Loved for a secure feel and light compression; many find these especially comfy during bloating or cramps.
• Boxer briefs: Gender-inclusive and great for full coverage—popular with teens, postpartum wearers, and those looking for a more relaxed fit.

Some brands also offer swim-friendly or activewear period underwear, which can be worn during workouts or water activities without compromising protection.

Related Post: Best Zero-Waste Toothpastes

How Does Period Underwear Work?

At first glance, period underwear looks just like regular underwear—but the magic is in the layers. High-quality, non-toxic period underwear is made with advanced fabric technology that allows it to absorb menstrual flow while keeping you dry, odor-free, and leak-free.

The Layered Fabric System

Most PFAS-free period underwear is built with three to four key layers:

1. Moisture-wicking top layer – Keeps you feeling dry by quickly pulling fluid away from the skin.
2. Absorbent core – Made of natural or technical fabrics that lock in blood, sweat, or discharge. Depending on the brand, this layer may hold 1 to 5 tampons’ worth of fluid.
3. Leakproof barrier – A breathable yet water-resistant layer (often polyurethane-free) that prevents stains from reaching your clothes.
4. Soft outer layer – Typically made of organic cotton, bamboo, or modal for a comfortable, non-irritating feel.

When choosing the best non-toxic period undies, look for materials that are free from PFAS, silver nanoparticles, and synthetic fragrances. Brands offering non-toxic cotton period underwear and organic period underwear often test their products for harmful chemicals and certify them through GOTS or OEKO-TEX®.

Reusable, Washable & Waste-Free

One of the biggest perks of toxic-free period panties is that they’re reusable. Most of us grow up using disposable pads and tampons without giving them a second thought. But the environmental cost? It’s staggering—and most people have no idea how serious it is.

Globally, it’s estimated that over 45 billion menstrual products are discarded every year. In the U.S. alone, the average menstruating person uses 11,000 to 16,000 pads or tampons in their lifetime.  

Most of these products are made with plastic, synthetic fibers, and non-biodegradable chemicals. This means they can take 500 to 800 years to break down in a landfill. And because they’re classified as medical waste, very few are eligible for recycling or composting.

Worse yet, disposable pads often contain up to 90% plastic, while applicator tampons can leave behind microplastics that end up in oceans and marine ecosystems. One 2022 report found that a typical box of pads contains the equivalent of 5 plastic grocery bags worth of plastic. 

When flushed or improperly discarded, menstrual products frequently clog sewage systems or get swept into waterways. Once there, they break down into microplastics, which are now being found in marine animals—and even human blood. It’s a full-circle contamination issue, and it starts with the products we use every month.

If just one person switches from disposables to non-toxic period underwear, they can prevent over 250 pounds of waste in their lifetime. Multiply that by millions of menstruators, and the impact is enormous.

With proper care, most non-toxic period products last 2–4 years, making them a smart investment for both your body and the planet.

Chemical-Free Period Underwear Was Found To Contain Toxic Chemicals.

Choosing reusable period underwear is a great step toward reducing waste. However, just because a product is eco-friendly doesn’t always mean it’s safe for your body. In recent years, several brands have come under fire for using harmful chemicals in their so-called “non-toxic period products,” raising serious concerns about what’s really hiding in your underwear. Lab tests commissioned between 2020 and 2022 by Mamavation and Environmental Health News revealed alarming results: 65% of period underwear, 48% of sanitary and incontinence pads, and 22% of tampons contained PFAS, the toxic “forever chemicals” linked to serious health risks.

The Thinx Lawsuit 

In 2023, Thinx—one of the most well-known “chemical free period underwear brands”—settled a class action lawsuit after independent testing revealed their products contained per- and polyfluoroalkyl substances (PFAS). These “forever chemicals” were not disclosed in their marketing, which claimed the underwear was “organic” and “non-toxic.” Consumers were understandably outraged, and the lawsuit led to growing demand for PFAS-free period underwear that’s been independently tested and transparently labeled.

While Thinx denied any wrongdoing in the settlement, the case highlighted a larger issue in the personal care industry: a lack of regulation and transparency when it comes to materials used in period products.

Knix Lawsuit

In April 2022, Knix was hit with a class-action lawsuit alleging false advertising and misrepresentation of product safety. The plaintiffs claimed that Knix marketed its “PFAS-free period underwear” as safe and free of harmful substances, while independent lab tests detected measurable levels of fluorine—a marker of PFAS—in some products. One reported result showed over 370 ppm of fluorine in a pair of Knix underwear, raising concerns about exposure to these so-called “forever chemicals.”

Knix denied knowingly using PFAS in its manufacturing but agreed to a $1.4 million settlement in late 2023 to resolve the case. As part of the settlement, the brand committed to refraining from making “PFAS-free” claims for two years unless it could provide scientific proof, and it also promised to strengthen its material testing practices. A separate California lawsuit involving Knix was voluntarily dismissed, but the earlier settlement terms still apply. This case reminded consumers that even well-known, wellness-focused brands aren’t immune to toxic chemical concerns.

Ruby Love Testing Controversy

While Ruby Love hasn’t faced a public lawsuit as of this writing, the brand came under scrutiny in 2021 after independent third-party lab tests detected 20+ parts per million of fluorine in their supposedly non-toxic period undies. Though this level is significantly lower than what was found in Thinx or Knix, it raised alarms among consumers and watchdog groups focused on PFAS contamination in intimate products.

The issue gained more attention when advocacy platforms and blogs flagged Ruby Love for failing to disclose details about its manufacturing processes or provide PFAS-free certifications. Despite no formal legal action, Ruby Love has yet to publicly confirm whether its products are tested for toxic chemicals—putting it on many cautious consumers’ “do not buy” lists until greater transparency is offered.

Why PFAS in Period Underwear Is So Harmful

PFAS (per- and polyfluoroalkyl substances) are a large group of synthetic chemicals—over 12,000 in total—used to make products resistant to water, oil, heat, and stains. Nicknamed “forever chemicals”, they don’t break down easily in the environment or the human body, meaning they can build up over time.

In reusable period underwear, PFAS is often added (intentionally or as manufacturing residues) to the moisture barrier layer to prevent leaks and stains. Brands may use them to make the fabric water-repellent, but they rarely disclose this to consumers.

PFAS may be present in period underwear for several reasons:

• To create stain-resistant or “stay-dry” finishes in the absorbent layer
• To strengthen leakproof membranes that block moisture from reaching outer clothing
• As a byproduct of DWR (durable water-repellent) treatments used in technical or performance fabrics, including sleeping bags.

While some brands intentionally add PFAS, others may have them as trace contaminants from treated materials or manufacturing equipment. Even if unintentional, these chemicals can still end up in the final product. As we previously explained, even the most popular PFAS-free period underwear brands might still add these chemicals to their panties.

P.S. Check out our complete list of PFAS products to avoid, here.

Health Risks of PFAS Exposure from Period Panties

PFAS exposure is linked to a wide range of health issues, especially because they can be absorbed through the skin and mucous membranes—making their presence in period products particularly concerning. According to research from the CDC and Environmental Working Group, PFAS are associated with:

• Hormonal disruption – including thyroid imbalance and estrogen interference
• Menstrual irregularities – such as longer or more painful periods
• Reproductive harm – including reduced fertility and increased risk of miscarriage
• Immune suppression – making it harder to fight infections or respond to vaccines
• Certain cancers – especially kidney and testicular cancer
• Developmental effects in babies and children – such as low birth weight and early puberty

A 2022 study published in Environmental Health Sciences highlighted the risk of dermal absorption of PFAS—particularly through vulvar tissue, which is thinner and more permeable than most skin. Wearing PFAS-treated fabric directly against this area for hours at a time, over many years, creates an exposure pathway that researchers are only beginning to fully understand. That’s the main reason why we should always opt for the best non-toxic period underwear in 2025!

Good news for California! A new law signed by Gov. Gavin Newsom will ban the sale of menstrual products containing intentionally added PFAS by 2025. By 2027, even trace amounts must stay below safe limits set by the state. This marks a major win for safer, non-toxic period products and public health.

Related Post: Best Non-Toxic Skincare Brands on Amazon

More Toxic Materials in Period Panties To Avoid

While PFAS have been in the spotlight, they’re not the only chemicals that may be lurking in some period underwear. Independent lab testing and investigations by environmental health organizations have uncovered a range of concerning substances in certain brands—many of which are either undisclosed or present as residues from manufacturing processes.

Here are a few of the most common—and problematic—chemicals found:

Flame Retardants

Flame retardants are sometimes applied during textile manufacturing, especially to synthetic fabrics like polyester or nylon. While their intended purpose is to reduce flammability, they don’t belong anywhere near intimate apparel.

Many flame retardants are known endocrine disruptors, meaning they can interfere with hormone function. Some have also been linked to neurodevelopmental delays in children, thyroid issues, and even increased cancer risk. There’s no justifiable reason for them to be in underwear, yet they’ve been detected in some mass-produced menstrual products. Other common sources are camping mattresses, and even play mats!

Azo Dyes

Azo dyes are a class of synthetic colorants commonly used in cheap or brightly dyed textiles. While not all azo dyes are dangerous, some can break down into aromatic amines—compounds that are carcinogenic and potentially harmful to the liver and bladder.

In period underwear, azo dyes may show up in the inner absorbent layer or outer fabric, especially in bold colors like red, purple, or black. Because the skin around the vulva is thinner and more absorbent, any prolonged exposure to dye residues raises red flags. It’s extremely important to make sure that our non-toxic period underwear is completely free of all Azo Dyes.

Formaldehyde

Formaldehyde is sometimes used as a finishing agent to make fabrics wrinkle-resistant or antimicrobial. But it’s also a known skin irritant and allergen and has been classified as a probable human carcinogen by the EPA and the International Agency for Research on Cancer (IARC).

Even low levels of formaldehyde can trigger contact dermatitis, especially in sensitive individuals or teens. In period underwear, it’s often found in synthetic blends or clothing treated for odor control or stain resistance.

What Is the Best Non-Toxic Material for Period Underwear?

The best non-toxic period underwear is made from natural, breathable materials that are gentle on the skin and don’t rely on synthetic chemical treatments. Here’s a breakdown of the safest, most sustainable options used in today’s toxic-free period panties:

Certified Organic Cotton Period Underwear

Certified organic cotton is widely considered the best material for non-toxic period panties It’s breathable, hypoallergenic, and grown without synthetic pesticides or GMOs. Because it’s free from chemical-heavy processing, it’s especially ideal for non-toxic period underwear for teens and anyone with sensitive skin.

Look for brands using GOTS-certified organic cotton, which ensures the fabric is processed without formaldehyde, heavy metals, or azo dyes. If you’re seeking non-toxic cotton period underwear, this is the gold standard.

TENCEL™ Lyocell

TENCEL™ Lyocell, made from sustainably harvested eucalyptus trees, is another excellent choice. It’s soft, lightweight, and produced using a closed-loop process that recycles almost all of the water and solvents. This makes it a great option for PFAS-free period underwear that also prioritizes eco-friendliness.

TENCEL™ is often blended with organic cotton for enhanced durability and moisture-wicking—perfect for those wanting the best non-toxic period undies with a more luxe, silky feel.

Bamboo  

Bamboo can be safe—but only if it’s mechanically processed. Many brands use bamboo viscose or rayon, which involves harsh chemical solvents like carbon disulfide during production. These chemical treatments can leave behind toxic residues, making them less suitable for truly non-toxic period panties.

Look instead for mechanically processed bamboo (sometimes labeled as “bamboo linen”) or brands that disclose their processing methods. It’s rare—but much safer.

Hemp Blends

Hemp is naturally antimicrobial, breathable, and highly durable—an underused but fantastic material for non-toxic period products. When blended with organic cotton or TENCEL™, hemp creates a supportive, moisture-wicking fabric ideal for heavy-flow underwear.

Plus, hemp requires less water and no pesticides to grow, making it a sustainable option for organic period underwear that’s both safe and environmentally conscious.

Certifications to look for in the safest non-toxic period underwear 

To be confident that your period underwear is truly non-toxic, look for these third-party certifications:

• GOTS (Global Organic Textile Standard) – ensures both organic farming and non-toxic textile processing
• OEKO-TEX® Standard 100 – screens finished fabrics for over 100 harmful substances
• MADE SAFE® – evaluates entire products for toxic chemicals linked to human and environmental harm

Brands that offer the safest period panties usually highlight these certifications clearly—and if they don’t, it’s worth asking.

*No FDA Oversight 

Despite being in direct contact with some of the most absorbent, sensitive tissue in the body, menstrual products—including period underwear—are not regulated by the FDA. That means brands are not legally required to disclose all materials or chemicals used in their products. 

This regulatory gap leaves consumers in the dark, trusting marketing claims without any enforcement or verification. A recent report that was posted 4 weeks ago by PAN UK and the Women’s Environmental Network found glyphosate—a pesticide linked to cancer—in tampons at levels 40 times higher than what’s legally allowed in drinking water. This is especially alarming because chemicals absorbed vaginally bypass the body’s natural detox systems, meaning even small amounts can pose serious health risks. The findings highlight the urgent need for non-toxic period products that are truly safe for our bodies.  

Recently, another study found arsenic and lead in organic and nonorganic tampons.  

Until stronger regulations are in place, the safest period panties are those that come from transparent brands using PFAS-free, toxic-free, and third-party certified materials—not just reusable, but truly safe.

Related Post: Best Clean Non-Toxic Chapstick Brands

Best Non-Toxic Period Underwear in 2025

1. Here We Flo Cotton Period Panties

• Non-Toxic Materials: Cotton certified by the ‘Better Cotton Initiative | Gusset lining: 100% Polyester | Gusset inner: 87% Polyester, 13% Polyamide | Lower Gusset: 100% Polyester with TPU Layer
• Types of Underwear: Hipster Briefs  
• Absorption Levels: Heavy flow  (4 tampons worth of menstrual blood)
• Size Range: S-3XL

Shop on Amazon – $19.99

I’ve tested a lot of non-toxic period underwear over the past seven years, and FLO’s Ultra-Absorbent Period-Proof Panties quickly became a favorite in my rotation—especially for heavy flow days. I also love that FLO uses sustainably sourced cotton through the Better Cotton Initiative and that 5% of profits go to people and planet causes. The brand is PETA-certified vegan and cruelty-free, and was founded by women of color, which is something I’m always happy to support.

These are designed to hold up to four regular tampons’ worth of blood, and while I rarely push any period underwear to the max, I felt confident in them from the start.

The fit is true to size and super comfortable. I fluctuate between a size XS and S, and their S felt snug but flexible, not too tight, and never restrictive. The high-waisted hipster cut offers great coverage without feeling bulky, and the fabric? Honestly, softer than some of my regular underwear. It has a cotton feel but with added stretch, which is ideal when you’re bloated or just want comfort without sacrificing support.

Absorbency-wise, they handled heavy gym sessions and overnight wear without leaks, though I do tend to check for dampness halfway through my day to be safe. I wouldn’t say they’re completely leakproof under extreme conditions, but they’re definitely leak-resistant enough for day-to-day use, including light workouts or errands.

One standout is the moisture-wicking layer that runs long from front to back—it gives you peace of mind if you move around a lot in your sleep or wear them during active days. I didn’t experience any chafing, rashes, or that dreaded sweaty feeling you sometimes get with synthetic layers. The FLO non-toxic cotton period underwear also didn’t hold on to odors after washing, which I really appreciate.

As for care: yes, you do have to get comfortable with rinsing them out. I rinse mine in cold water and toss them into a mini washer I keep just for my non-toxic period undies.

2. Bambody Bamboo Period Underwear

• Non-Toxic Materials: 95% rayon derived from bamboo,5% spandex
• Types of Underwear: Hipster Briefs and Bikini
• Absorption Levels: Medium to Heavy Flow (4 tampons worth of menstrual blood)
• Size Range: XS-6X

Shop on Amazon – $34.99

Bambody surprised me in the best way. I initially tried them because they had over 9.000 glowing reviews on Amazon, and I’d heard good things about their comfort and value, and they definitely delivered. Especially for those looking for non-toxic period underwear or leak protection during postpartum, perimenopause, or light incontinence.

First off, they’re thin and discreet, but hold a lot—up to four regular tampons’ worth. I wore them with yoga pants and under leggings during workouts, and they didn’t show through or slide down. The fit was secure and flattering, and I loved that they come in fun colors—a small but much-appreciated break from the usual all-black options.

The 4-layer design is smartly done: it feels like regular underwear, but it actually performs better than some “premium” brands I’ve tried. The full-coverage leakproof layer goes front to back, so you’re protected whether you sleep on your back or stomach. I didn’t have any leaks or discomfort, even on longer days when I wasn’t near a bathroom. While I personally don’t have super heavy periods, I found Bambody’s non-toxic period panties incredibly useful for pelvic floor leaks and hormonal changes post-exercise—and they absorbed even more than I expected.

As for care, it’s pretty straightforward: I rinse them and throw them in a mesh bag with my laundry, then air-dry them to keep them in good shape.  They’re also FSA/HSA eligible, which helps offset the cost, especially if you’re planning to stock up.

P.S. I always recommend having at least three pairs of non-toxic period panties so you’re not caught mid-cycle without a fresh one.

3. Saalt Period Underwear for Heavy Flow

• Non-Toxic Materials: TENCEL Modal
• Types of Underwear: Boyshorts, briefs, bikini
• Absorption Levels: Light, Regular, Heavy, and Super Heavy  (3 pads and 4 tampons worth of menstrual blood)
• Size Range: XS-XL

Shop on Amazon – $47

I have been using Saalt’s period cups for years, so I had pretty high hopes for their PFAS-free period underwear. It’s the first boyshorts-style pair I’ve worn. The fit is perfect—secure around the thighs and waist without squeezing or riding up—and the TENCEL™ Modal fabric is next-level soft. It’s light, breathable, and somehow manages to feel cozy and dry even during a heavy flow.

These are rated to hold the equivalent of 3 pads or 4 tampons, and honestly, I pushed those limits on a heavy day and overnight, and they held up with zero leaks. What really impressed me is their gusset technology—it wicks moisture away instantly, so you don’t get that sticky or soggy feeling that some other brands leave behind. You really can’t feel the absorbent part, which helps avoid that bulky “diaper” sensation some people worry about.

The extended gusset in the boyshort design makes it ideal for overnight use or when you’re just not taking any chances, like road trips. They stayed in place all night—no rolling or bunching—which for me is non-negotiable.

And of course, Saalt walks the talk when it comes to being non-toxic. Their underwear is not treated with PFAS, and they use sustainably sourced, renewable beechwood fibers, which aligns with my values and what I look for in non-toxic period products. They’re also a certified B Corp and give back 2% of sales to menstrual equity initiatives—another reason I keep supporting them.

If I had to nitpick, I’d say the dry time is a bit longer than some other pairs I own, but that’s just the trade-off for truly absorbent, multilayer protection. I just make sure to wash and hang them ahead of time so I always have a dry pair ready.

4. Goat Union Period Panties

• Non-Toxic Materials: Outer: 95% viscose made from bamboo, 5% spandex; Inner: 95% cotton, 5% spandex; Absorbent: 80% polyester, 20% nylon; Leakproof: 100% breathable polyester TPU
• Types of Underwear: Shorts, briefs, swimwear, boyleg, boxer briefs, slip shorts
• Absorption Levels: Heavy flow (4-5 tampons’ worth of menstrual blood)
• Size Range: XS-6X

Shop on Amazon – $28

If there’s one thing I won’t compromise on during my period, it’s leak-free sleep—and these Goat Union overnight period shorts seriously deliver. Designed with a full front-to-back absorbent panel, they offer maximum protection for heavy flow nights, and for the first time in ages, I didn’t wake up paranoid about staining my sheets. They hold up to 4 regular tampons’ worth of flow, and I’ve even used them for postpartum leaks and mild bladder incontinence—they’re that versatile.

I love that the brand focuses on the “3 Highs”: high absorbency, high function, and high material safety. The fabric is OEKO-TEX and SGS certified, which means it’s rigorously tested for harmful chemicals—no PFAS, no toxins, and no unnecessary irritation. If you’re transitioning to non-toxic period products, these shorts are a great addition, especially if you want something that’s both eco-conscious and effective.

That said, I treat these as loungewear or sleepwear only. They feel like regular shorts, but the absorbent layers do make them a bit thick, and they tend to bunch up a little when walking around. One important tip: size up for extra comfort, especially if you’re cramping—no one wants pressure on their lower belly during that time of the month.

The biggest win? I can fully free-bleed overnight in these without a second thought. No pads, no tampons, just breathable coverage that lets me sleep comfortably and confidently. 

5. WUKA Organic Cotton Period Underwear

• Non-Toxic Materials: BCI-certified & GOTS-certified cotton, TENCEL modal, elastane, polyester, recycled nylon
• Types of Underwear: Midi Briefs, hipster, bikini briefs, high waist, swimwear, thong, cycling, shorts, boxer short, sleep overnight, leggings, shorts
• Absorption Levels: Light, Medium, Heavy, & Super heavy (12 tampons worth of menstrual blood)
• Size Range: XXS-6X

Shop Wuka – From $18

Next is a PFAS-free period underwear brand from the UK! I tried the WUKA Ultimate Bikini while I was in London last year for an aerial skills retreat. I was wearing this pair for 6 hours straight during my classes, and it performed amazingly well. It holds up to 20ml of flow, which is about 4 tampons’ worth, and honestly—it’s one of the few pairs I feel totally confident wearing for a full 8 hours with no backup. The high-cut bikini fit is flattering and doesn’t dig into my hips, which makes them a go-to under everything from leggings to lounge pants.

What I appreciate most about WUKA is its commitment to non-toxic materials. These are made from GOTS-certified organic cotton, meaning the fabric is grown without chemical fertilizers, GMOs, or pesticides—a huge win if you’re trying to switch to non-toxic cotton period underwear. The fabric is soft and breathable, so there’s no irritation, no rashes, and no synthetic weirdness rubbing against your most sensitive skin.

They don’t feel bulky, and there’s no weird plastic-y crunch like with some other brands. I wore these on a medium-to-heavy flow day during a long walk and stayed dry, odor-free, and comfortable the whole time. They’re also part of WUKA’s Ultimate™ collection, which uses the brand’s most sustainable production methods, so you’re making an impact with your purchase too.

6. Modibodi Cotton Period Underwear

• Non-Toxic Materials: Oeko-Tex Standard 100 certified 95% Organic Cotton / 5% Elastane | Gusset: Top Layer: 100% Merino Wool | Middle Layer: 80% Polyester / 20% Polyamide | Bottom Layer:100% Polyester
• Types of Underwear: Boyleg, thong, brief, swimwear
• Absorption Levels: Light, Moderate, Heavy, Super Heavy (10  tampons worth of menstrual blood)
• Size Range: XS-2X

Shop Modibodi – From $26

The B-certified corporation Modibodi was one of the very first chemical-free period underwear brands I’ve ever bought.  Their inclusive sizing, PFAS-free period panties, and commitment to breaking period taboos really stood out to me, especially after I saw their now-famous ad showing actual menstrual blood (finally!). The underwear is made from sustainable bamboo and merino, which feels super soft on the skin, and I love that everything ships in compostable packaging—a big plus for anyone trying to cut down on period waste.

I tried the Maxi briefs on a heavy night (day 2 of my cycle) and was impressed—they claim to hold up to 10 tampons worth, and honestly, I believe it. During my initial absorbency test, the flow sat on top for a bit, which made me nervous, but once I actually wore them, no leaks, no wetness, and no discomfort. The fit was secure and cozy for overnight use, and I didn’t wake up in a panic like I used to with pads.

One standout feature I didn’t expect to love as much as I do? Their leak-proof swimwear. It’s genuinely life-changing for beach days on your period—no more awkward tampon changes in public restrooms. If you’re looking for non-toxic, sustainable, and reliable period underwear free of chemicals that actually meets the demands of real life, Modibodi is a strong contender.

7. The Period Company Underwear

• Non-Toxic Materials: Body: 95% Organic Cotton with 5% Spandex Jersey | Absorbent Layer: 100% Polyester | Leak Resistant Layer: 100% Polyester PUL
• Types of Underwear: Bikini, high-waisted, sleeper shorts, 
• Absorption Levels: Light, Moderate, and Heavy (9 tampons worth of menstrual blood)
• Size Range: XS-6X

Shop period company – From $6

The period company underwear came to my radar only a month ago, while I was visiting Los Angeles.  I grabbed a pair from their Santa Monica location. These PFAS-free period underwear are made with soft organic cotton and a 4-layer absorbent core that holds up to nine tampons’ worth—impressive for the price point. They’re also third-party tested by Intertek for organic and toxic-free standards, which gave me peace of mind, especially knowing how unregulated some mainstream products can be (seriously—400+ FDA defect warnings on tampons are wild).

Wearing the full coverage brief, I immediately noticed how secure and breathable it felt. During my absorbency test, most liquid was soaked up fast, though a small amount did sit on the surface, so while they’re solid on their own, I’d personally pair them with a cup on heavier days for extra backup. That said, for lounging or lighter flow, they’ve become one of my go-to options.  

8. Revol Cares

• Non-Toxic Materials: Inner: 92% Bamboo 8% Spandex | Gusset 1: 70% Bamboo 30% Organic Cotton | Gusset 2: Breathable Cotton PUL | Outer: 92% Bamboo 8% Spandex  
• Types of Underwear: Thong, super-high-rise boy shorts, super-high-rise briefs 
• Absorption Levels: Light, Regular, Moderate, Ultra, Super, Super +
• Size Range: XS-7X

Shop Revol – From $29

If you are a plus-size girly on the hunt for the best non-toxic period undies in 2025, Revol is for you. Out of all the PFAS-free period underwear I’ve reviewed thus far, this one is the most size-inclusive, going up to 7X. Revol Cares gets major points for being thoughtfully designed and super user-friendly. I love that they use soft, breathable bamboo and are PFAS-free (independently tested!). The style quiz on their site was a surprisingly helpful touch—it matched me to the right cut and absorbency based on my needs, which saved a lot of second-guessing.

Fit-wise, the underwear is stretchy but secure, and the fabric feels high-quality, luxurious without being bulky. During my absorbency test, they soaked up most of the liquid well, though I did notice a slight surface dampness after a few hours, especially on heavier flow days.

Personally, I wear them solo on light-to-medium days and pair them with a cup or disc if I need more coverage. They’ve held up great through multiple washes and are a perfect pick for anyone who wants clean materials and a personalized fit—plus, if you’re in Canada, the local shipping is a huge win.

9. Period Aisle Organic Cotton Period Undies

• Non-Toxic Materials: Body: 48% TENCEL™ lyocell, 48% organic cotton, 4% spandex | Gusset: 90% Truetex™ (88% recycled polyester, 12% organic cotton), 10% TPU | Lining: 86% recycled polyester, 14% organic cotton
• Types of Underwear:
• Absorption Levels: Light (Essential), Adjustable (BOOST), and Heavy (Super – 8 tampons worth of menstrual blood).
• Size Range: XS-5X

Shop Aisle – FROM $48

Remember lunapads period underwear? They are now officially known as Period Aisle, a B-certified brand that has been doing this longer than most, and it shows in the thoughtful design and reliability of their non-toxic period panties. I tested the boxer style, and it’s quickly become my go-to for the first couple of days of my cycle when I want full coverage and no shifting.

The fabric is soft and breathable thanks to OEKO-TEX-certified organic cotton and TENCEL™ lyocell. It feels snug but never tight, which is ideal when I’m bloated or cramping.

During my absorbency test, it soaked up three full droppers easily, and the material stayed surprisingly dry to the touch with minimal transfer. They’re certified PFAS-free period underwear, which gives me the confidence to wear them regularly, and I also love that they come in styles beyond the typical brief, even thongs and boxers. These are perfect for anyone who wants dependable leak protection, clean materials, and comfortable all-day wear.

10. Dear Kate Period Underwear

• Non-Toxic Materials: Fabric content: 76% Nylon, 24% LYCRA® (body) / 90% Micro polyester, 10% Elastane (lining)
• Types of Underwear: Briefs, hipster, thongs
• Absorption Levels: Light, Medium & Heavy (3 tampons worth of menstrual blood)
• Size Range: XS – 3X

Shop Dear Kate – From $6

Dear Kate is known as one of the best non-toxic period underwear brands in 2025! I was genuinely impressed with how lightweight and breathable these feel while still offering solid backup protection. With three layers of Underlux™ technology, they hold up to 3 regular tampons’ worth, and I’ve found them perfect for light days, spotting, or pairing with a cup or tampon on heavier days. There’s no crinkly plastic, no stiffness, and best of all—no panty lines under leggings or jeans.

What makes Dear Kate stand out for me is the versatile range of cuts—they’re one of the few brands that actually let you wear thong-style or sporty cuts during your cycle without sacrificing peace of mind. The Hazel Hipster Full has a flattering bikini-style fit that feels like regular underwear but performs like a true period safety net. I’ve worn these to hot yoga, on travel days, and just lounging at home—no shifting, no leaks, and no irritation.

They also have a clear PFAS-free period underwear statement and avoid using PU/PV films, which gives me serious confidence in wearing them daily—even on non-period days to manage discharge or sweat. These are a great option if you want something discreet, sleek, and safer for your body.

More Non-Toxic Period Panties

• TomboyX – TomboyX is a gender-inclusive underwear and apparel brand founded in 2013, known for its size-inclusive (3XS-6L), body-positive designs, and commitment to sustainable, non-toxic materials. While they don’t specialize in period underwear, they do offer moisture-wicking, comfortable styles that are PFAS-free and suitable for menstrual comfort or light leak protection.
• Boody Period – Boody Period is a line of eco-friendly period underwear made from soft, sustainable bamboo viscose and designed to offer light-to-moderate flow protection with moisture-wicking and odor-blocking layers. Completely PFAS-free and produced under ethical, OEKO-TEX-certified standards, they’re a reliable, non-toxic option for everyday comfort during menstruation.
• Lilova – Lilova is a subscription-based, non-toxic period underwear brand offering size-inclusive, blendable underwear and pads designed for light to heavy flow protection, with an emphasis on affordability and sustainability. Proudly PFAS-free, made with breathable fabrics, and offering flexible coverage options, Lilova focuses on comfort, convenience, and eco-conscious period care. 
• Innersy – Innersy is a budget-friendly chemical-free period underwear brand offering high-waisted and hipster styles made from soft, breathable cotton blends with a leak-proof midlayer—OEKO-TEX certified and PFAS-free. With sizes from XS to 5XL and real-world users praising its comfort and dependable leak protection, Innersy is a popular choice for light to moderate flow days, postpartum, or bladder leaks.

Cotton Period Underwear I Don’t Recommend

• Thinx – I own a pair of Thinx undies, and they work pretty well. However, I don’t recommend Thinx as a non-toxic period underwear brand because of past concerns about PFAS (per and polyfluoroalkyl substances) in their products. Independent testing in 2020 found fluorine—a marker for PFAS—in some pairs of Thinx underwear, raising red flags about potential chemical exposure. Although Thinx has since released updated products and claims to have removed PFAS, they settled a class-action lawsuit in 2023 without admitting wrongdoing. Until they provide consistent third-party testing and transparency, I suggest opting for brands that are certified PFAS-free and openly share lab results.
• CORA period underwear – The brand mentions that “Cora period underwear is made without PFAS. Yet, they do contain 14 & 13 parts per million (ppm) fluorine.
• Red Ruby Box – The Red Ruby Box is not on my list either, as it was found to contain 27 ppm & 22 ppm fluorine.

What is the Best Way To Clean Period Underwear?

This is the most common question I get every time I mention PFAS-free period panties to, well, everyone. Washing them the wrong way can shorten their lifespan or, worse, damage the absorbent layers and introduce unwanted chemicals.

Here’s a simple, step-by-step guide to safely cleaning your non-toxic period underwear:

Step 1: Rinse in Cold Water ASAP: As soon as you take them off, rinse with cold water until the water runs clear. This helps break down the blood before it sets and keeps stains at bay. Avoid hot water—it can set the stain and damage the fabric’s absorbency.

Tip: You can rinse them in the sink or even take them into the shower with you to save water.

Step 2: Hand Wash or Use a Gentle Cycle: If hand washing, use a mild, fragrance-free detergent like Blueland. If machine washing, place your period underwear in a mesh laundry bag and choose the delicate cycle with cold water.

Avoid fabric softeners, bleach, or harsh stain removers—these can break down the protective layers and compromise the “non-toxic” nature of your undies.

Step 3: Skip the Dryer: Always air-dry your period panties. High heat can ruin the elastic, shrink natural fabrics like organic cotton, and weaken the waterproof barrier. You can hang them up or lay them flat to dry. Bonus: it’s better for the environment and your energy bill.

Step 4: Repeat and Rotate: To extend the life of your collection, rotate between multiple pairs. Most safe-period underwear can last 2–5 years with proper care.

Yes, it’s that simple!

How to Transition to Period Panties (Without Stressing Out)

Let’s be honest—switching from pads or tampons to non-toxic period underwear can feel a little intimidating at first. I’ve been there. You wonder: Will they leak? Will I feel wet? Will they work on my heaviest days? The good news? You don’t have to go all in overnight. Transitioning slowly is not only totally normal—it’s smart. Here’s how I did it, and how you can too:

• Week 1–2: Start small. Pick 1–2 pairs of non-toxic period panties and wear them on your lightest flow days or as a backup with a tampon or cup. This helps you get used to the feel and fit without the fear of leaks.
• Week 3–4: Add more pairs into your rotation and try them on moderate flow days. Keep a backup product on hand (cup, disc, or pad) just in case while you’re still learning how much coverage you need.
• By Cycle 2 or 3: You’ll likely have a good idea of what absorbency levels and styles work for different days. That’s when most people start phasing out their old products for good—especially once they realize how freeing and low-maintenance chemical-free period underwear really is.

Start on Light Day First

Light days are your testing ground. I wore my first pair of organic cotton period underwear on day 5 of my cycle, just to run errands and lounge at home. It helped me build trust without pressure. Choose a pair with light or moderate absorbency, and make sure it’s snug (but not tight) around the legs for leak prevention.

Blending With Other Products on Heavy Days

Even now, I sometimes pair my PFAS-free period underwear with a menstrual cup on my heaviest days or overnight hikes. There’s no shame in mixing methods—this isn’t an all-or-nothing switch.

Think of your undies as your safety net:

• Use them under a cup or disc for leak protection
• Combine with an organic cotton pad on day 2 or 3 if your flow is intense
• Pair with tampons during travel when frequent changes aren’t possible.

This flexible approach keeps your routine low-waste and low-stress.

How to Prevent Leaks (Tips That Work)

1. Choose the Right Absorbency. Not all period panties are made equally. Look for brands that offer absorbency levels labeled clearly (light, moderate, heavy, overnight). For heavy flows, I personally love double-layered gussets or styles with full-back coverage.

2. Use Backup Liners Strategically. On your heaviest days, wear a non-toxic panty liner or organic cotton pad on top of your underwear as extra insurance. You’ll likely never need it, but it boosts confidence—especially in public.

3. Overnight Tip: Lay a Towel (Just in Case). When you’re new to the switch, lay a towel or use a mattress protector at night. I did this during my first cycle until I found which pairs gave me true overnight protection (look for styles labeled “overnight” or “super”).

More Non-Toxic Period Products to Consider

• Menstrual Cups: Reusable, long-lasting, and zero waste, menstrual cups are a fantastic alternative to non-toxic period underwear.  Look for medical-grade silicone cups like Saalt Cup or DivaCup that are tested for safety and free from PFAS, BPA, latex, and dyes.
• Organic Cotton Pads: Disposable pads don’t have to mean toxins. Many conventional pads are treated with fragrances, chlorine, or plastic-based materials, but these organic cotton alternatives keep it simple: Natracare is certified organic, plastic-free, and totally chlorine-free, Rael is an organic cotton top sheet, tested for PFAS, Cora – Offers GOTS-certified cotton pads with transparency in sourcing.
• Cloth Pads: Think of these as reusable versions of your regular pad—made from non-toxic fabrics like organic cotton or bamboo. Many options like LunaPads (now Aisle), GladRags, and Hannahpad are handmade or come from small ethical brands.
• Menstrual Discs: Unlike cups, menstrual discs sit higher in the vaginal canal and can be worn during sex. Some brands are disposable, while others are reusable. Again, opt for medical-grade silicone discs, not those made from plastic-based polymers. Cora Disc, Nixit and Flex Reusable Discs are all amazing picks.
• Organic Cotton Tampons: Choose tampons made from 100% GOTS-certified organic cotton, without rayon, plastic applicators, or chemical residue. Some of my favorite brands are LOLA, Natracare, and TOP (The Organic Project).

For more non-toxic beauty and personal care product reviews, check out:

• Best Non-Toxic Sunscreens
• Is There a Natural Alternative to Hairspray? 
• Natural & Non-Toxic Allergy Relief Tips
• Safest Non-Toxic Baby Lotions

FAQS About PFAS-Free Period Underwear Without Chemicals

Final Thoughts on the Best Non-Toxic Period Underwear Free of PFAS

This was my full review of the best non-toxic underwear for 2025! While period underwear is a more eco-friendly option than disposable pads, not all brands are safe for your skin. Many still contain PFAS, toxic “forever chemicals” linked to cancer, hormone disruption, and immune issues. To protect your health, always choose non-toxic period undies made with organic cotton, chemical-free fabrics, and verified PFAS-free certification from third-party labs or transparent brand disclosures. Look for organic cotton period underwear that’s breathable, well-fitting, and suited to your flow—some offer light to heavy absorbency levels, while others are better as backup on your heaviest days.

If you’re shopping for non-toxic period underwear for teens, prioritize comfort and size inclusivity. At the end of the day,k choosing the safest PFAS-free period underwear means knowing what’s in them—and making sure they’re as gentle on your body as they are on the planet.

Konstantina Antoniadou, Chemicals & Health Expert

Senior Writer, Product Researcher & Tester

Konstantina Antoniadou is an expert sustainability writer, certified in Chemicals and Health by Johns Hopkins University, where she focused on the toxicity of commonly found household chemicals and their health impacts. She has also completed specialized studies in Sustainable Fashion (Copenhagen Business School), Business Models for Sustainability (BMS), and Sustainable Development Goals (University of Copenhagen), deepening her expertise in the connection between personal choices and global environmental change. With years of experience as a senior writer and researcher, Konstantina now leads our reviews of non-toxic home products, beauty and skincare brands, and sustainable fashion. K. is also the creator of the popular 7-Day Non-Toxic Living Challenge, downloaded over 2,000 times and praised for its accessible, science-backed tips.