Thinx for All press release image via PR Newswire

These menstrual alternatives claim to be a clean and comfortable solution to inconvenience and leaks, but at what cost?

Thinx introduced the concept of period underwear to the masses, a washable, reusable panty that could soak up blood in place of a tampon or pad. A decade after its launch, Thinx has been hit with a class action lawsuit that claims their products contain harmful chemicals that may have long term negative health effects on consumers.

20-year-old Natalie Salas, a chemical engineering student at the University of Illinois-Chicago (UIC), decided to try Thinx in 2020 to implement into their lineup of menstrual care as a backup option while switching to menstrual cups.

“I was really interested in wearing something comfortable and reusable so I do not have to use disposable pads or tampons again,” they said.

Abigail Suleman, MPH in Maternal and Child Health Epidemiology at UIC, purchased Thinx during a sale, also with the intention of a backup to menstrual cups. Both Suleman and Salas advocate for greater access to menstrual products on campus through Blood Buds, a student-run organization at UIC co-founded by Suleman. 

Dickens, et al. v. Thinx Inc., filed in May 2022, alleges the presence of per-and polyfluoroalkyl substances (PFAS) in Thinx’s period underwear. PFAs are man-made chemicals that over time continue to build up in the environment – and in the body – earning the name “forever chemicals.”

“Once these chemicals are used and in the environment, they stay there forever,” said Dr. Sung Kyun Park, associate professor in the Departments of Epidemiology and Environmental Health Sciences at the University of Michigan, Ann Arbor. “It’s almost impossible to break down these chemicals.”

Consumers react to Thinx lawsuit

Period panties have become increasingly popular as the menstrual health industry expands. The market alone is projected to bring in $279.3 million globally by 2026, and according to the U.S. Chamber of Commerce, Thinx holds 70% of the market share in the U.S.

“From the NYC subway to the pages of Vogue, we’re one of the most well-known, awarded, and recognizable period and incontinence underwear brands out there” reads Thinx’s website. 

According to the lawsuit, “Through its uniform, widespread, nationwide advertising campaign, [the] Defendant has led consumers to believe that Thinx Underwear is a safe, healthy and sustainable choice for women, and that it is free of harmful chemicals…  In reality, Thinx Underwear contains harmful chemicals… which are a safety hazard to the female body and the environment.”

Salas did not participate in the settlement, while Suleman did.

“I did not have the receipts for my purchase and even then, I would have received a fraction of what I paid for the period underwear,” said Salas.

Suleman explained, “I think that I will personally still use them until I can afford to replace them or news comes out that my style of underwear does not contain the PFAS.” 

Salas said they would also continue to use their Thinx underwear. 

“Things happen like this all the time. I was and am disappointed that another company claims to be for reproductive health and freedom, then proceeds to use materials that can negatively impact reproductive health,” said Salas. “The news does not change how I use the product. As much as I care for the health of others, for myself I will continue to use my Thinx period underwear.” 

Suleman says she is disappointed in the brand and that there is a sense of guilt among menstrual equity groups that have promoted the use of Thinx underwear to clients, or even provided them to people experiencing period poverty.

“I also felt bad about recommending them and purchasing some for my own friends.”

The risks associated with PFAS

The CDC points to changes in liver enzymes, decreased vaccine response in children, and increased chances of kidney and testicular cancer as some of the health effects linked to PFAS in the blood system. Based on his own studies, Dr. Park says the build up of PFAS also leads to higher risk of other chronic diseases, like diabetes

“It can affect your lipid levels, your glucose level, for women and even for men, it could interfere with your hormones,” he explained, citing one of his studies that linked higher blood concentration of PFAs in women to earlier menopause.

“Menopause is not a disease but scientific evidence suggests that women who reach menopause earlier are more likely to develop hypertension, cardiovascular disease and other diseases – that’s why early menopause is a big problem,” he explained.

We are exposed to PFAS more than we realize, says Dr. Park. From period underwear to nonstick pans to food wrappers, manufacturers use PFAS to make products stain-resistant, nonstick and waterproof. 

He says that women are more at-risk to PFA exposure, because many of the products that contain them are marketed directly to women and used on a daily basis, including makeup and beauty products.

In fact, according to a 2021 study, 63% of foundations, 55% of lip products and 47% of mascaras tested positive for high levels of fluorine, an indicator of PFAS.

These chemicals bind to protein in the blood and circulate throughout the body. While more at-risk, Dr. Park says women also have more ways to release PFAs because they can flow out of the body during that time of the month.

“Bleeding is one of the most important excretion mechanisms,” he says, citing blood donation and breastfeeding as other ways PFAs are eliminated from the body.

Dr. Park said there aren’t any human studies that investigate whether PFA contact exposure to the vaginal area is especially harmful.

Thinx has agreed to pay $4 million to the settlement fund but denies all allegations made in the lawsuit, telling The New York Times that PFAS have never been a part of their product design, but that the company will take measures to help make sure PFAS are not added to their product.

The settlement class includes anyone who purchased Thinx underwear from November 12, 2016 to November 28, 2022. Consumers are responsible for filing to be included in the settlement class if they’d like to be compensated for products they bought. Class members who submit claims can receive $7 for up to 3 pairs of underwear with proof of purchase or $3.50 for up to three pairs without proof. Thinx’ classic collection of underwear cost ranges from $25 to $38.

Other companies, like Simply Orange Juice and CoverGirl Cosmetics, have also been hit with class action lawsuits for false advertising and containing PFAS. Dr. Park believes that regulating PFAs alone isn’t going to solve the problem because companies find loopholes to use the chemicals.

“PFAs should be regulated as a class, not individual chemicals. The entire [class of] PFAs should go away from consumer products.”

When Rebellious asked if he saw this happening anytime soon, he responded, gently shaking his head, “Absolutely not.”