Comparing 3 Popular PFAS-Free Period Underwear Brands & My Top Pick!

Comparing Two Popular PFAS-Free Period Underwear Brands & My Top Pick! (Modibodi, The Period Co.)

Are you interested in giving period underwear a try? Or perhaps you’re a former Thinx user looking for new, safer options. Either way, I got you! This post will cover everything you want to know about period underwear, frequently asked questions, how it works, and the best brands.

This post contains affiliate links.

Table of Contents:

Period Underwear FAQ & Why I Love Them 🩸

If you’re new to period underwear or want to know what makes them better than traditional pads, let’s go over that real quick!


  • Absorbent, moisture-wicking, and leak-proof
  • Super comfortable! And you don’t have to worry about pads shifting or detaching in your panties.
  • Cost-effective! It’s an initial expense upfront but will save money in the long run by not having to buy disposable products every month.
  • I actually feel CLEANER and more hygienic when I use period undies compared to pads or pantiliners, even the organic ones. They tend to feel more breathable.
  • Reusable, low waste, and better for the environment! Think of how many single-use sanitary products you would regularly use during a menstrual cycle. It totally adds up!
  • Conventional pads and menstrual products can be made with plastics, bleach, pesticides, or synthetic fragrances. So using a high-quality brand of period undies can be an easy way to avoid that.

Related post: “Tampons, Pads, Menstrual Cups…Oh My! Are There Toxic Chemicals in Your Feminine Products?

FAQ & How to Take Care of Them:

How do you wash period undies?

It will depend on the brand and type of fabric. In general, treat them as delicates!

  • After wearing a pair, run it under cold water in the sink and gently squeeze out any extra liquid (don’t soak for an extended time!)
  • Wash on the cold/gentle cycle setting
  • Use a delicate garment bag to keep them separated from anything that could snag
  • Don’t use any fabric softeners or strong detergents (here are my go-to natural laundry picks!)
  • Avoid putting them in the dryer at high temperatures. Hang drying is best, but if you do use the dryer, make sure it’s on the lowest/coldest setting.
  • Once they’re completely dry, you can keep them in a drawer or somewhere dry and protected
How often should you change your undies? Can you sleep in them?

You can absolutely sleep in them, they’re just like regular underwear 💤

It will depend on your flow for how often you need to change them! And the type of underwear you’re wearing (they come in various absorbencies!). Kind of like when you wear a pad, you’ll be able to tell when it’s “full” or heavy and it needs to be changed. If you’re on a super heavy day, it may be 4 hours or so. On a lighter day, you can probably go the whole day!

How long do they last?

If you take good care of them, they should last for at least a year or two, but usually way longer than that!

Will they smell funky?

If cared for correctly, they shouldn’t stink or have any foul odors. If they sit out for a long time before washing and fully drying, then they could smell mildewy or musty. You can always dilute white vintage in a thin layer of water (1:3 ratio) and gently rinse/rub the fabric in the solution. Don’t let it soak for more than 15 minutes or so. Then wash like normal!

How much blood do period undies hold?

Again, it depends on the style of the undies; they typically come in Heavy, Moderate, or Light absorbencies. The heaviest ones can sometimes hold roughly 9-10 tampons worth or up to 50 mL!

Can you wear period panties with a cup or tampons too?

Yep! You can mix and match and do whatever you prefer. You can the undies alone or with a menstrual cup/tampons depending on your flow and preference. For example, I mostly use them as a backup to my menstrual cup and on my lighter days because I personally prefer that!

Can period undies be used for postpartum, incontinence, or bladder leaks?

You betcha 💦 Some brands even offer styles made exclusively for these situations.

Work with Becca: Custom Consult

Why I Stopped Using Thinx 🛑

If you’ve been reading this blog for a while, then you’ll know that I was a big fan of Thinx period undies for the longest time! They were pioneers in the menstrual underwear movement and really put them on the map. Many people may see reusable sanitary products as gross or weird (I used to!), but Thinx definitely helped destigmatize the concept!

However, you might know that they were involved in a lawsuit due to PFAS being found on their products. Major bummer! If you’re not familiar, PFAS (or PFOA) are poly-fluoroalkyl substances known as “forever chemicals” and are incredibly harmful to humans. According to the EPA, these chemicals are persistent, long-lasting/break down very slowly, and pose various health risks such as reproductive toxicity, developmental effects, an increased risk of certain cancers, and a reduced ability for the immune system to fight infections. They’re no joke!

Not only that, but I didn’t love it when Thinx changed their materials. They used to use organic cotton and moved towards cheaper, more synthetic materials. Overall, I just didn’t feel like their quality was as good as it used to be, and was curious to try something different!

PFAS-Free Period Panty Brands I Tried Instead…

Once the news broke about Thinx, I wanted to test out some new brands! There are a lot of underwear brands on the market these days so it can be overwhelming.

Mamavation did extensive testing and provided a list of PFAS-free period underwear that had no fluorine detected. I picked brands from that list that were the most intriguing to me.

So if you’re looking to switch to cleaner, non-toxic alternatives instead, you’re in the right place! I tested them out for a couple of months. Keep reading for my review of each, pros/cons, and which is my ultimate favorite!

Brand 1️⃣: The Period Company

What intrigued me about this company is how affordable their undies are! Most of the styles are $9 or $12. I had seen some people share about Period Co. and seemed to enjoy their products, so I bought some to try!

Period Company Period Underwear

Styles I Tested: The Heavy Period Bikini, The Heavy Period High Waisted, The Bikini Period (medium), The Thong Period (light)

Materials: A mix of polyester, cotton, organic cotton, microfiber, nylon, and spandex (third-party tested free of PFAS)

Fit: Mostly true to size, maybe a little on the big side


  • Comfortable
  • Budget-friendly
  • Ship from within the US
  • They do absorb very well
  • Have styles for teens/juniors
  • Use organic cotton in some styles
  • The heaviest styles hold a lot of liquid (up to 9-10 tampons worth)
  • “2-Period Guarantee” where you can get your money back if you’re not satisfied after using them for two cycles

Heavy Period Underwear The Period Co. Organic Cotton


  • I do like that they use some organic cotton but most of their fabrics are synthetic unfortunately
  • Not a ton of cute styles, patterns, or colors available. Most of the underwear is black and very plain. Some come in other colors but are usually sold out.
  • The heavier styles feel sort of bulky. They definitely soak up liquid well, but they do feel a bit diaper-y. The high-waisted style even feels kind of saggy in the butt area.
  • I don’t want to say they’re poorly made because that’s not true, but I can tell they’re just not as…luxurious? I don’t know how to describe it exactly. For example, one of the styles has a weird open flap on the inner/front part. Not a huge deal at all, they’re just not the most chic undies out there!

Overall, if you’re not looking to spend a ton of money and just want something more basic, you’d like these! Or if you have a really heavy flow.

Shop Period Co. Undies Here

Also available here on Amazon.

Related post: “12 Sustainable Fashion Brands for a Conscious Wardrobe (& All Budgets!)

Brand 2️⃣: Modibodi

Modibodi is an Australian brand that I’ve been curious to try for a few years now. They put a big focus on sustainability, impact, and giving back.

Modibodi Period Undies

Styles I Tested: Classic Bikini (light-moderate), Classic Full Brief (moderate-heavy), Sensual French Cut (moderate-heavy)

Materials: A mix of bamboo viscose, merino wool, Tencel, GOTS-certified organic cotton, recycled polyester, and spandex (OEKO-TEK certified and third-party tested free of PFAS)

Fit: True to size


  • They do absorb well
  • Fairly and ethically made
  • Have styles for teens/juniors
  • Super comfortable and extremely soft (softer than Period Co.)
  • 60-day trial where you can get a refund on a pair if you’re not satisfied
  • Tons of cute styles and fun colors/patterns! Many of them don’t even look like period undies.
  • Use mostly sustainable and natural fibers; they even have an entirely biodegradable collection
  • Granted I haven’t tried their heaviest overnight styles, but the moderate-heavy ones don’t feel bulky at all. They seem thinner and more seamless compared to Period Co.

Modibodi Period Underwear


  • More expensive compared to Period Co.
  • Their heaviest styles don’t hold as much as Period Co.’s
  • After a few months, I noticed minimal pilling on the outside fabric of one of my pairs
  • Ships from Australia which isn’t the most eco-friendly thing if you live in the US (but you can buy on Amazon too)

If you’re trying to be conscious about materials and sustainability and don’t mind spending a little more money, Modibodi is awesome!

Shop Modibodi Period Undies Here

Also available here on Amazon.

Brand 3️⃣: Poppins Period

As a long-time user of Poppins Period’s menstrual cup, I was excited when they launched period undies! The brand was founded by two sisters who both felt the physical and financial burdens of menstrual cycles and wanted to offer positive and purposeful period products.

Poppins Period Underwear

Styles I Tested: Right now they only make one style!

Materials: Underwear is cotton and modal (a semi-synthetic cellulose fiber), absorbent layer is polyester (OEKO-TEK certified and third-party tested free of PFAS)

Fit: True to size, looser waistband


  • They do absorb well
  • Ship from within the US
  • Super lightweight and breathable fabric
  • Don’t show much of a VPL (visible panty line)
  • Hold as much as a menstrual cup (more than 5 tampons)
  • Safe to tumble dry (most other brands require air drying!)
  • “Better Period Promise” where you can get a refund or replacement within 60 days if you’re unhappy
  • Most period undies have a black liner whereas Poppins’ is speckled with some white/gray, which I actually like because you can better gauge whether they are full and need to be changed or not

Poppins Period Underwear


  • Waistband is kind of flimsy and loose
  • More expensive compared to Period Co.
  • Only available in one style and color (black)
  • The liner is a bit stiff at first (but does loosen over time) and I do wish it were wider
  • Gusset on the butt area doesn’t go up very high so they might not be the best option if you want extra heavy coverage

I hope Poppins expands to offer more styles, colors, and absorbencies in the future! But I am happy with these for the most part and think they’re a solid option, especially if you’re also going to buy a menstrual cup or other period products from Poppins.

Use code ORGANICALLYBECCA for a discount 🏷️

Shop Poppins Period Undies Here

My top pick: Modibodi! 🏆

In terms of absorbability (is that even a word? it is now!), all three of these brands work well and get the job done; I’ll continue to wear them each month. I truly don’t miss my Thinx at all.

But if I had to pick a favorite? I prefer Modibodi overall because they use really nice materials, have more color/style options (I like pretty things!), and are high quality. Thumbs up from me! 👍

Have you tried any of these brands? I’d love to hear about your experience or if you have any questions about period underwear in general. You can drop a comment below. Thanks for reading 💚

Becca Signature



Comparing Two Popular PFAS-Free Period Underwear Brands & My Top Pick!

Written by: Becca

Becca is a blogger, wife, and dog mom living in Milwaukee, Wisconsin. Having seen firsthand the benefits of switching to a natural lifestyle herself, she's passionate about helping women make the switch to clean beauty products, organic skincare, and a holistic way of life (without the stress of being perfect about it!).

15 comments on “Comparing 3 Popular PFAS-Free Period Underwear Brands & My Top Pick!”

  1. Oooo the modibodi ones look luxurious! And I love those materials. I also used thinx! They were quite an investment (I have probably 7 thongs and 4 overnights plus a few of the heavy flow bikini cut.) I’m reluctant to stop using them for this reason, but safety is safety. I’m so bummed! And really glad you did this post to educate me. Have you reached out to Thinx in terms of a refund? I think I might so I can reinvest in safe products.

    1. Yeah I know it’s tough! There was a settlement and you were able to submit a claim to get some money back from Thinx but unfortunately I think it’s closed now and you can’t submit any claims anymore.

  2. How do you know if a company uses PFAS in them? I’ve been using Saalt and Knix brands but can’t find anything conclusive online.

    1. Hi! Usually if you go to a brand’s FAQ section on their site, they might include info about that, and sometimes will share third-party test results. If not, you could always reach out to the brand’s customer service!

  3. I believe the open flap inside the Period brand is supposed to be for a small heating pad (if I remember correctly)
    I appreciate your info, and I think I’ll be switching to Modibodi now to at least try out!

  4. Have you noticed any of the brands having a weird smell to them? I had a brand that used the bamboo viscose, and I noticed a weird smell that I couldn’t get out (from the beginning even after wash and wear).

  5. All of the information on these chemicals is so overwhelming. I see that these are free of PFSAs, but what about BPA? For instance:
    “Spandex is made from several chemicals that are known sensitizers. TDI and MDI (Toluene-2,4-diisocyanate; Methylene bisphenyl-4,4-diiisocyanate) are precursors of the polyurethane used to make spandex. TDI, a toxic chemical, has proved carcinogenic and can cause severe dermatitis. MDI is also toxic.”

    Cotton, Nylon, Spandex and Allergies – Hospital

    1. Hi Lisa, your best bet to avoid BPA is to choose the most natural fibers possible. Also note that spandex is usually used in really small amounts in clothing, it’s needed to make it stretchy and elastic. I know it can be overwhelming when you start going down the rabbit hole but also keep in mind that there’s no way to be 100% perfect or avoid every single toxin out there.

  6. Just wanted to say thank you for writing this. I haven’t invested in myself in this way ever and I’m 46! I am happy to say that I decided today to “treat” myself and try to make my time of the month a little less…..uh not so great. I wanted to ask some friends what they use, but didn’t want to wait on answers to trickle in, so I searched out inexpensive PFAS free period panties and found you! I’m so pleased. I ordered The Period Co. and will see how it goes and maybe try out the other two. Thanks again.

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