Pads, pants or cups: Which period product is the most climate-friendly?

Twenty billion disposable menstrual products are discarded each year in the US. There's a huge array of reusable options, from pads to pants to menstrual cups. Ana Santi explores which is the most sustainable and how safe they are.

During a weekend away with my girlfriends a few years ago, one of them mentioned that she was wearing period pants, an environmental decision to move away from single-use pads and tampons. I'd vaguely heard of them, but didn't know anyone who wore them and I'd always been a little sceptical – would they be absorbent enough? My friend convinced me otherwise and they've remained my product of choice ever since. But as I browse the shelves of menstrual products in my local supermarket today, I'm overwhelmed by the choice available: so many pads and tampons (some organic, most not), numerous types of cups, a few period pants.

And still, 49 billion single-use period products are used every year in Europe alone. In the US, it's about 20 billion discarded each year, generating 240,000 tonnes of solid waste. Globally, disposable sanitary pads – which can contain up to 90% plastic and end up largely in landfill –are the most commonly used menstrual product.

I set out to find the most sustainable period product available.

Given that 1.8 billion people across the world menstruate every month, a group of academics based in France and the US conducted a life-cycle assessment of menstrual products across four product groups: disposable non-organic and organic pads and tampons (with applicators); reusable pads; period underwear; and menstrual cups, which are made from soft, flexible silicone or rubber and can hold 20-30ml (around two tablespoons) of menstrual blood. Comparing eight environmental impact indicators – global warming potential, fossil resources, land use, water use, carcinogenic effects, ecotoxicity, acidification and eutrophication – and conducted over one year across three countries (France, India and the US), the assessment considers impacts from production to disposal.

Across all the three countries and environmental impacts, the menstrual cup was a clear winner, followed by period underwear, reusable pads and, in last place, single-use pads and tampons. Small and lightweight, one person's menstrual cup can last up to 10 years.

Disposable pads – both organic and non-organic – had the highest impacts across all eight categories except water use, with non-organic pads scoring the highest for global warming potential and resource depletion. The global warming potential – greenhouse gas emissions' ability to absorb heat and warm the atmosphere over a given time period – came from manufacturing, with almost half of the impact from production of polyethylene (a petroleum-based plastic). But one of the most surprising results – not least to the report's authors – was that organic cotton pads had the highest impact of all, across five categories.

"The impacts are mostly linked to raw material manufacturing and organic production, which can have higher environmental impacts," explains Mélanie Douziech, one of the study's co-authors from Mines Paris-PSL university. The yield of organic farming is lower than conventional farming, meaning more water and land is needed to produce the same amount of organic as conventional cotton. Similar results were found for organic and non-organic cotton tampons.

Depending on the product, different parts of the lifecycle influence the emissions. "For disposable products, it's the raw material production and manufacturing, as a lot of these products have plastics in them, which have quite a large global warming impact," says Douziech. "With reusable products, it is the manufacturing and use phases, especially the electricity requirements."

Water and electricity are needed to wash all reusable products between wear, but period pants perform better than reusable pads, in part because otherwise another form of underwear would be worn – and washed – regardless. "Even though the menstrual cup is a clear winner, period underwear is also an alternative product that really reduces the environmental impacts," says Douziech. How we care for them can also affect the overall impact, such as washing at lower temperatures and as part of a full load.

The assessment did not consider plastic pollution, but according to the study each conventional pad, including wrappers, wings and adhesives, adds some 2g of non-biodegradable plastic — the equivalent of four plastic bags — to the environment and take an estimated 500 to 800 years to decompose. The study adds that, in the US, 80% of conventional tampons and 20% of conventional pads are flushed down toilets, blocking sewers and releasing microplastics into oceans.

Prior to this report, an analysis of several life-cycle analyses comparing the environmental impacts of menstrual products, including emissions and resource depletion, was commissioned by the UN Environment Programme in 2021. Co-author Philippa Notten, director of the Cape Town-based non-profit TGH Think Space, which focuses on energy, climate change and sustainability projects, says that, due to a lack of data, the impact of plastic at menstrual products' end of life is not well documented in life-cycle assessments. "Plastic tends to get modelled as if it ends up in a landfill or incinerator. Counterintuitively, landfill actually looks good from a carbon footprint point of view because plastic takes hundreds of years to degrade, so those carbon emissions are locked up in the landfill, which acts like a carbon sink," she says. "In reality, the product doesn't always end up in a formal waste management stream; it ends up as litter on beaches, as microplastics in the sea. And there is still a lot of carbon in the production of plastics." 

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In UNEP's report, the menstrual cup also comes out on top by a considerable margin. "It's quite rare for this to happen to a product," Notten says. "It's not that the cup doesn't have a carbon footprint, but because it's such a small, light product, the impact is also small relative to other products."

"We always talk about 'break even points' in these studies: how many times do you have to use a renewable product before it has made up for the emissions caused in its manufacturing and use phases, compared to a single-use product?" Notten says. "For many products, it's often really high, like 100 times. With a menstrual cup, you only have to use it for a month before it breaks even on its carbon footprint."

Both studies express the importance of context and highlight that greenhouse gas emissions are only one of the many consequences of products and processes. "No matter what we do, we are going to have an impact, but the idea is to minimise this impact as much as possible," says Paula Pérez-López, co-author of the France and US study and a researcher at Mines Paris-PSL university.

The life-cycle assessment recommends that women consider factors beyond environmental impact, including social and cultural attitudes and infrastructures. "This was out of our field of environmental assessment expertise, but in some African countries, reusable products, in particular menstrual cups, could be the difference between going to school and not for some girls, who don't have access to a period product," says Pérez-López. "Of course, the problem of access extends to all kinds of products, but a menstrual cup could be much easier to access because it's a small product that lasts a long time."

But recent reports have warned of the consequences of a poorly fitted, incorrectly sized menstrual cup, with one woman developing temporary kidney problems and some women suffering from pelvic organ prolapse. Shazia Malik, consultant obstetrician and gynaecologist at the Portland Hospital in London, is reluctant to recommend menstrual cups to teenagers unless they are carefully taught how to use and care for them. "In the last eight years, I've seen patients – women and teenagers – who use menstrual cups develop infections," she says. "If you don't insert [the cup] properly, it can compress the bladder or rectum, and it won't effectively collect menstrual blood."

Malik also warns of the dangers of using the same menstrual cup for many years. Her advice is to have two cups on the go, sterilise them after each use – including every morning and night – and to replace them as soon as there is any wear and tear. "We also need more awareness on choosing the right menstrual cup size, depending on your flow and whether you've had a vaginal birth. With education, the menstrual cup is a fantastic period product," Malik says.

In the UK, the Women's Environmental Network, a non-profit, is calling for a Menstrual Health, Dignity and Sustainability Act to combat period poverty, environmental waste and toxic chemicals found in period products. WEN cites a new policy in the Spanish region of Catalonia as an example to follow. From March 2024 all women in Catalonia were given access to free, reusable menstrual products.

Among the network's concerns is a US study that detected 16 types of metals, including lead, in tampons, and a report by Which?, a UK consumer magazine, which found "unnecessarily high levels of silver" in some period pants, used as an antimicrobial agent to combat concerns about smell and hygiene.

Helen Lynn, a campaign manager focusing on the environmental impacts of menstrual products at WEN, says that such chemicals are harmful to human health and the environment, with innovation happening faster than regulation. "[The life-cycle assessment] is an interesting study but it doesn't take into account chemical residues and additives in menstrual products because businesses aren't obliged to disclose them, so studies like these can only look at the main materials disclosed by manufacturers," she says. "A lack of transparency means that people don't know what's in these products and they put them next to a very absorbent part of the body."

Some legislative progress is being made, with Europe leading the way. In September 2023, the European Commission established a new EU Ecolabel criteria for absorbent hygiene products and reusable menstrual cups, awarded to products that fulfil limit environmental impacts along their lifecycle. In Nordic countries, the Nordic Swan Ecolabel, which promotes resource efficiency, reduced climate impact, a non-toxic circular economy and conservation of biodiversity, is currently in a consultation period to revise the criteria of its sanitary products.

In 2024, Vermont became the first US state to adopt a new law to ban the "forever chemicals" PFAs in menstrual products, while a bill led by New York congresswoman Grace Meng calls for the National Institutes of Health (NIH) to study the make-up of menstrual products.

Marina Gerner, professor at New York University's Stern School of Business and author of The Vagina Business, would welcome a US equivalent to the EU Ecolabel, but is calling for a global initiative. "Companies need to disclose the ingredients of their period products and toxic ingredients need to be banned by regulators," Gerner says. "The reason this hasn't happened yet is because women's health has historically been under researched and underfunded. The modern tampon was invented in 1931 and the first study on metal levels in tampons was only published last year."

Several years ago, I switched to mostly using period pants. They last between two to three years and cost about £45 ($56.7) for three pairs. At approximately £2.75 ($3.48) for a pack of 10 pads, and using two packs per month, I would have spent up to £200 ($252.7) on pads in the same period. A menstrual cup is approximately £20 ($25.2) and, for people comfortable using tampons, it is relatively easy to insert, but removal, cleansing and re-insertion when away from home or in public toilets can make it less accessible.

As a regular swimmer, I plan to try period swimwear next, although the possibility of leakage makes me anxious (I've been assured by people who wear them that this doesn't happen). Even though the life-cycle assessment ranked disposable organic products as the worst environmental offender, on occasions when period pants aren't convenient, I use a disposable, organic cotton, plastic-free and compostable brand that you can discard in your food bin (it is readily available in supermarkets and health stores). Pérez-López says that the study did not model composting at end-of-life. "This would need to be investigated further." 

When trying to make better environmental choices, it is rare to find a relative silver bullet, like the menstrual cup. But I think that most people who are in a position to choose their menstrual products would prefer a range of options. "And that is a great solution," says Pérez-López. "Choose a reusable product when you can, but if you're uncomfortable using a certain type of product for your whole cycle, or you can't rely on a reusable product for a particular reason, combine several products. You will still be making a difference."

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