Does Thinx Underwear Contain Toxic Chemicals?

In the last few years, the menstrual care market has grown significantly. Thanks to a rise in brands offering menstrual cups, period pants, reusable tampon applicators, and more, people who menstruate have more plastic-free options than ever.

But a new lawsuit has many asking the question: can these supposedly sustainable brands actually be trusted?

New York-based Thinx first emerged on the underwear scene in 2013. It instantly attracted attention, because it offered a refreshing take on dealing with periods: absorbent underwear that could be washed and reused over and over again. Even better, it was made “carefully and consciously,” with non-toxic, sustainable materials and an ethical supply chain.

The brand didn’t invent the concept of period panties, but it certainly helped to popularize them. And by 2017, after first launching from a humble Kickstarter campaign, it was turning over nearly $40 million in revenue.

But it turns out, Thinx might not all be as that it seems. Earlier this month, the company ended up settling a class-action lawsuit regarding the presence of per- and polyfluoroalkyl substances (PFAS) in its underwear.

The problem with PFAS

PFAS can be found in everything from non-stick pans to carpets, and they’ve even been found in children’s school uniforms. But research suggests that these chemicals (which are human-made water-, heat-, and oil-resistant) are far from non-toxic. In fact, they have been associated with an increased risk of certain cancers, as well as liver damage, asthma, and decreased fertility.

They’re also a risk to the environment, as they do not break down over time, and can contaminate waterways. (One recent study found freshwater fish are particularly at risk of PFA contamination.)

Thinx claims that it did not engage in “improper or unlawful” behavior regarding the use of PFAS, which are also known as “forever chemicals,” but did agree to compensate those who bought Thinx products between 2016 and 2022.

The brand also stated that “it will continue to take measures to help ensure that PFAS are not intentionally added to Thinx Period Underwear at any stage of production.”