The Best Period Pants In The UK (PFAS Free) Tested

Looking to make the switch to reusables? I’ve tried out lots of different non-toxic period pants brands in the UK to help you find the best ones.

Most conventional sanitary products are made of plastic – with one pack of disposable sanitary towels containing as much plastic as the equivalent of 5 plastic carrier bags. Even tampons have plastic in them.

As well as being made of fossil fuels, period waste is a huge environmental problem. An estimated 200,000 tonnes of sanitary products are estimated to end up in landfill in the UK each year. And single-use sanitary products are the fifth most common item found on Europe’s beaches, as many are incorrectly flushed down the loo.

Thankfully, there are a whole host of eco-friendly period products out there to help you make more sustainable choices. I’ve tried a lot of different options over the years, and whilst I do love reusable period pads (cups not so much), the real winner for me is reusable period pants. These are easy to use – with no learning curve – and suit most people.

However, period pants are an investment, and making the right choice is key. To help you find the best pair for you I’ve tried and tested five of the leading period pant brands, to find the very best ones. As toxic chemicals are a huge problem in period pants, I’ve only tested PFAS-free brands. And if you don’t know what PFAS is, don’t worry, I cover all of that in the next paragraph.

What To Know About PFAS In Period Underwear

In the guide, I mention brands that are PFAS-free. PFAS stands for Perfluoroalkyl and Polyfluoroalkyl Substances.

These chemicals are added to a variety of products to make them water-resistant, stain-resistant or greaseproof. So, for example, your waterproof jacket or boots may be coated with PFAS to repel water.

So far so innocuous, right? I’m afraid not. The problem with PFAS is that they are terrible news for both human health and the environment.

PFAS are known as forever chemicals because they do not break down in the environment. They persist, meaning they build up and don’t go away. And they are linked to several health concerns, including fertility problems, an increased risk of cancer, and more. When it comes to wildlife, these chemicals cause similar issues.

In 2020 Jessian Choy from Sierra Club shockingly found that period pants, from brands such as Thinx, contained these PFAS.

In January 2023, Thinx settled a lawsuit brought against it. Whilst Thinx said that the settlement was “not an admission of guilt or wrongdoing”, it has said that customers who submit valid claims to buying Thinx products between 2016 and 2022 can receive $7 per purchase for a maximum of three purchases.

Given the huge difference between wearing a pair of waterproof shoes coated with PFAS and period pants that fit tightly on your sensitive intimate parts, I’ve gone to lengths to find what I believe are PFAS-free period pants.

My Testing Process

When it came to working out which brands to test, I immediately discounted testing any brands that did not have a specific “zero PFAS” policy on their website. That immediately ruled out quite a few brands. I also ruled out brands where I wasn’t convinced their products were made ethically.

I’ve tried out several different period pants over lots of cycles to find my favourites. Some I’ve been wearing for years, so know all the ins and outs of them, others were tested for at least 2 months. I then use the following criteria to rate them:

• how absorbent and effective they are
• how comfortable they are
• their price
• their quality
• what they are made of
• who made them
• their durability
• how long they take to dry

Guide To The Best PFAS-Free Reusable Period Pants

Ready to wear, wash and repeat? With an increase in both the number of brands and styles of period pants available, it can be daunting knowing where to start, so here are my top picks.

WUKA

⭐Best period pants on a budget

WUKA is a female-led start-up that offers heaps of different period pant options to help you have a sustainable period, whatever your preferences.

This inclusive brand offers pants catering for 4 different flow rates – from light to super heavy. Its period pants also cater for UK sizes 4 to 26, in various styles, to suit your needs best. Pants come in two colours – black or nude – and in various prints.

Wendy Says

I’ve been using WUKA period pants for six years now, and I love how durable they are. I’ve not had to replace them yet, despite repeated wear, making them a sound investment.

They are incredibly effective, and I’ve never had a leak yet. I particularly love wearing them at night time, for a comfortable and secure night’s sleep.

Comfort-wise, they are super soft and stretchy. These period pants aren’t too bulky and don’t chafe or rub. It’s easy to put them on and forget you are wearing any period protection. I’ve also found they offer a smooth silhouette, even under tight-fitting clothes such as leggings.

Of all the pants I own, I’ve found that my Wuka ones take the longest to dry after washing. In summer I dry them outside, and it’s not a problem, but in winter I dry them on the clothes horse, and they can take two days to fully dry out.

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Modibodi

⭐Best period pants catering to the widest range of absorbencies

Created for different bodies, and different flows, Modibodi offers a wide range of reusable PFAS-free period pants in a range of styles, colours, and flow levels in UK sizes 4 – 26.

Modibodi primarily uses organic cotton, mulesing-free merino wool, bamboo viscose, and pre-consumer recycled nylon to make its pants. This means Modibodi’s core range of underwear isn’t vegan, however, a vegan range is available.

This award-winning brand is the first reusable period pant brand to create adaptive underwear for people with disabilities. Here, the hook and loop tape fastening makes changing simple and stress-free whether standing, sitting, or lying down.

Wendy Says

I’ve been using Modibodi’s period pants for around two years now, and I’m so impressed with how absorbent, comfortable, soft and slim they are. I haven’t experienced any leaks, even overnight or on the heaviest days of my period. They are also still looking in great shape, even after two years of repeated wear.

What I also love is having the option to choose between standard black knickers or fun colours and designs. It makes these pants feel a bit more fun than having a drawer full of standard-issue black knickers. I have bought a few lacey pairs, and I love how luxurious they feel. They don’t look like period pants, and make me feel great when I put them on.

And I find these wash and dry well – in winter they tend to dry within a day on my clothes horse.

I’d love to see Modibodi move away from using spandex to more sustainable options, but on the whole, I applaud its use of sustainable fabrics. What I also appreciate is that if you try Modibodi for the first time and don’t like your pants, you can return them and get your money back.

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Fluxies

⭐Best for vegan-friendly period pants

Fluxies offer size-inclusive period pants, in UK sizes 4 – 30, that are all PFAS-free, in a host of styles. From classic bikinis to hipsters and sleep shorts, there’s something for every preference.

Fluxies says that it is committed to creating products that are designed with sustainability at the core – from the natural fibres it uses to the ethical manufacturers it partners with – with zero compromises on comfort, form, or function.

Fluxies prioritises ethical fabrics, including organic cotton, and super soft and breathable Tencel, and does not use any animal products in its period pants.

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Saalt

⭐Best period pants for low-flow days

Saalt is a newcomer to the UK market. Well-established in the US, this B Corp’s new UK shop caters for UK sizes 4 – 24.

Saalt uses silky soft recycled fabrics made of post-consumer recycled water bottles to make its pants. And from the fabric to the finishes, Saalt supports ethical sourcing and manufacturing processes at every step of its supply chain.

Its ethically-made fabrics are made in a renowned factory that guarantees safe and healthy labour conditions and goes above and beyond to provide housing, medical care, safe water, and scholarships for its seamstresses and workers.

Saalt offers a range of different styles- bikini briefs, thongs, and high-waisted briefs. And each style has four colours to choose from – giving you ample choice.

Saalt’s period pants are incredibly thin (the thinnest period pants by a mile), lightweight and smooth. I found they don’t give a dreaded VPL under tighter clothing, such as leggings. They look and feel just like regular pants – there’s nothing that screams period underwear.

I tried out the leakproof high-waist briefs. These offer regular to heavy flow protection.

I did find these period pants super soft, and super comfortable and I loved how thin they are. However, after just one hour of wear on day one of my period, I experienced a leak. I wouldn’t say I have a particularly heavy flow, so it was disappointing to find they had leaked after such a short duration, particularly as these were the most expensive pair I tried.

Saalt says these pants can replace two pads, but this sadly wasn’t my experience. Through trial and error, I’ve found that they are better suited for daytime use during the lighter flow days at the end of my period. Here they are perfect – the thinner pants provide the protection I need without necessarily feeling like I’m wearing period pants.

If you need to use panty liners at any point in the month, then I also think these would make a great reusable alternative.

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Hey Girls

⭐Best for period pants that give back

Hey Girls is an award-winning period product social enterprise that wants to eradicate period poverty in the UK. That means each order is matched with an equivalent donation to someone in need.

With five styles available and a range of sizes from 6 – 22, Hey Girls period pants are made from bamboo and organic cotton fabric. This is lined with an extra super absorbent layer.

Wendy Says

I think these bamboo period pants are ideal for those starting out and exploring the world of period pants. They are super soft and comfortable to wear, and I haven’t experienced any leaks through 18 months of testing them. I’m not surprised though – these are the biggest pants by far that I’ve tested and definitely cover you up!

Despite their size, they aren’t particularly bulky – but aren’t quite as thin as my Modibodi ones. I’d say they take around a day and a half to dry in winter on a clothes horse.

One pair started to fray at the waistband quite badly after just a few months of wear. However the other Hey Girls pairs I own are faring well through repeated washing and wearing, so I don’t know how representative that one pair is of the overall quality.

I love the fact that each purchase helps to reduce period poverty. However, because of their size, they look very much like period pants. Sometimes on day two of your cycle that’s exactly what you need. And sometimes, by day four, it’s good to wear different styles that don’t quite scream “I’m on my period”. Just me?!

Other Non-Toxic Brands

If you’re looking for more PFAS-free brands, I’ve come across the following brands which all claim they are free from harmful chemicals such as PFAS. I haven’t tested these brands though, so I don’t have any first-hand experience of how they perform:

• Cheeky Wipes
• Flowette
• Snuggs

Need More Info?

Still on the fence about period pants? Do check out my beginner’s guide to period pants that covers all the questions you might have about period pants, including those questions you might be too afraid to ask.