‘Forever Chemicals’ Detected in Reusable Feminine Hygiene Products

Reusable menstrual products—once hailed as eco-friendly and health-conscious alternatives to disposables—may be hiding a chemical threat, according to a new study.

Researchers from Indiana University and the University of Notre Dame have discovered evidence of per- and polyfluoroalkyl substances (PFAS), commonly known as “forever chemicals,” in a wide range of reusable feminine hygiene products.

The study involved the testing of 59 products from North America, South America and Europe. These included period underwear, reusable pads, menstrual cups and reusable incontinence underwear.

Last year, researchers led from the Harvard T.H. Chan School of Public Health in Boston analyzed menstrual hygiene habits using data from the Apple Women’s Health Study, which tracked 11,455 U.S. participants between November 2019 and January 2024.

Despite rising awareness about arsenic and toxic metals, regular tampons remained the most commonly used menstrual product, used by 48 percent of subjects.

Pads were used by 47 percent and panty liners by 43 percent. Among reusable options, period underwear was chosen by 20 percent and menstrual cups by 18 percent of respondents.

Recently, the researches found PFAS were detected in nearly 30 percent of the samples—at levels suggesting they were intentionally added. This marks the first official confirmation of these potentially harmful chemicals in reusable menstrual products.

“Since reusable products are on the rise due to their increased sustainability compared to single-use products, it’s important to ensure that these products are safe. This is crucial, especially for adolescents and young women, who are more vulnerable to potential negative health effects,” said paper author and chemist professor Marta Venier of Indiana University in a statement.

“Feminine hygiene products stay in contact with the skin for extended periods of time, and the risks from the dermal absorption of PFAS, especially neutral PFAS, are not well understood.”

What Are PFAS and Why Are They Concerning?

PFAS are synthetic chemicals used for their water, stain and heat-resistant properties. However, they are known to accumulate in the human body over time and have been linked to serious health conditions, including hormone disruption, cancer and immune system dysfunction.

“One of the most abundant PFAS detected in products from the North American market is 8:2 FTOH, a chemical that was voluntarily phased out in food packaging by manufacturers in accordance with the FDA due to persistence in the body after dietary exposure,” explained Sydney Brady, a Ph.D. student in Venier’s lab.

“Notably, 8:2 FTOH can be transformed into more toxic PFOA once inside the body.”

Newsweek reached out to Dr. Olivia Ahn, a former NHS doctor based in the U.K., who described the idea of chemicals and microplastics entering women’s bodies as “unsettling.”

“It’s a serious concern that demands urgent attention from everyone involved – from the companies making these products to the regulators overseeing them,” she said.

Ahn, founder of the sustainable femcare brand FLUUS—which developed the world’s first certified flushable, microplastics- and glue-free sanitary pad made from non-woven natural materials—explained how these substances are absorbed through sensitive tissues.

She said: “The vaginal tissue isn’t like the skin on your arm—it’s incredibly delicate and acts like a fast track directly to your bloodstream. It’s highly absorbent, meaning chemicals can quickly get into your system without being filtered by your liver or digestive system in the usual way.

“This pathway is so efficient that it’s even used in medicine for quick drug delivery. This unique sensitivity is precisely why we must be extra vigilant about the chemical makeup of products designed for intimate use. What you put there really matters for your overall health.”

Environmental Implications of Reusables

While reusable menstrual products are seen as a sustainable alternative to disposables, they still end up in landfills. Once there, PFAS can leach into the soil and water, posing a wider environmental hazard.

These findings underline the need for greater transparency in product manufacturing and labeling.

“Consumers should know that not everything that is in a product is listed on the package,” Venier added.

“Increased transparency from manufacturers would help consumers make informed decisions about what they’re purchasing for themselves and their families.”

Do you have a tip on a health story that Newsweek should be covering? Do you have a question about PFAS? Let us know via health@newsweek.com.

References

Wang, Z., Peebles, E., Baird, D. D., Jukic, A. M. Z., Wilcox, A. J., Curry, C. L., Fischer-Colbrie, T., Onnela, J.-P., Williams, M. A., Hauser, R., Coull, B. A., & Mahalingaiah, S. (2025). Menstrual product use patterns in a large digital cohort in the United States: Variations by sociodemographic, health, and menstrual characteristics. American Journal of Obstetrics and Gynecology. https://doi.org/10.1016/j.ajog.2025.03.002

Wicks, A., Brady, S., Whitehead, H. D., Hedman, T., Zachritz, A., Venier, M., & Peaslee, G. F. (2025). Per- and Polyfluoroalkyl Substances in Reusable Feminine Hygiene Products. Environmental Science & Technology Letters. https://doi.org/10.1021/acs.estlett.5c00553