How worried should you be about the ingredients in tampons?
This article was originally featured on Undark.
A video about titanium oxide in tampons became viral on TikTok .. A blonde woman was holding a large package of tampons. She suggested that the mineral could cause period cramps, ovarian cysts and irreversible damage to the uterine.
Research conducted on rats has found that titanium dioxide is harmful if inhaled in large quantities, and the European Union has banned the mineral as a food additive over possible health concerns. However, its safe use in food and personal-care products is maintained by the US regulators. In response to the TikTok turmoil, doctors and journalists at major outlets–including USA Today, Gizmodo, and CBS News–as well as health and wellness websites, jumped in to dispel the tampon rumors. “Titanium dioxide isn’t making tampons into toxic death sticks,” wrote OB/GYN Jen Gunter on her popular women’s health Substack, The Vajenda.
But, the fracas raised serious questions about tampon ingredients. Only a few scientists have been able to identify potentially harmful compounds in certain menstrual products. However, companies are not legally required by law to disclose their ingredients to US customers. Even if brands provide a list, there are not many conclusive studies to help consumers understand the implications for their health if they do not disclose the ingredients.
Researchers spoke with Undark and stressed that there is little evidence to suggest that tampons cause harm when they are used as directed. However, researchers pointed out that it’s normal for lay people to wonder about the contents of their menstrual products. This is especially true when scientists are asking similar questions.
“Knowing the ingredients and their implications and what they might do for your body is a good starting point.” Inga Winkler, an associate Professor at the Central European University, Vienna, says that knowing the ingredients and the consequences might be a bad idea. “And the fact we are fighting about it, I mean .”
About a decade ago , Marianthi Anna Kioumourtzoglou had been chatting with two other researchers regarding the possibility of pesticides in military’s cotton uniforms. Then, she realized it was time for her to change her tampon. Kioumourtzoglou noticed a connection between the discussion and her personal life while in the bathroom. “Tampons are made of cotton. Cotton is a source of pesticides. She wondered, “What did I just put in me?” Kioumourtzoglou returned to the conversation and asked: “Have any of you ever heard about tampons ?”
Kioumourtzoglou is a trained air pollution epidemiologist and was particularly interested in glyphosate, a pesticide that farmers spray on their cotton plants. The US Environmental Protection Agency says that when properly used, glyphosate poses “no risks of concern to human health.” But in 2015, the International Agency for Research on Cancer, part of the World Health Organization, classified the chemical as “probably carcinogenic” based on limited evidence in humans, but sufficient evidence in experimental animals. These mixed conclusions–combined with the cotton plant’s ability to absorb heavy metals–led Kioumourtzoglou to wonder if pesticides, particularly glyphosate–in cotton fibers can make it through the tampon manufacturing process. She is now an associate professor of environmental science at Columbia University’s Mailman School of Public Health. She recalls feeling frustrated when she tried to find answers but nothing came up.
To really get to the bottom of the matter, Kioumourtzoglou stated that researchers must ask several questions. First, are there any toxic chemicals in tampons? If so, at what levels? Second, are these chemicals able to leach from tampons into the body and be absorbed? Do they have any adverse effects on the health if they are absorbed?
The first question requires basic research. This involves taking apart tampons to determine what’s in the cotton stuffing. This has been attempted by a few scientists over the past two decades. The results showed that many tampon brands contain potentially toxic substances, but at very low levels.
One early study, published in 2002, calculated the concentration of dioxins in four brands of tampons. Dioxins are a byproduct of the process of whitening rayon. This semisynthetic fiber is added to some tampons in order to increase their absorbency. According to the EPA and U.S. Food and Drug Administrations, long-term dioxin exposure above a certain threshold can have adverse effects on reproductive health and cause birth defects. The study found trace amounts, but much lower than the levels found in dietary exposure, of dioxins in all tampons. These results were replicated in a 2005 study.
In 2020, a separate research group looked into a class of chemicals called volatile organic compounds, or VOCs, which are often used to make paint thinners, petroleum fuels, and household cleaning products. These compounds are often added to tampons because they can absorb moisture and mask odor. The researchers, based at the University of Michigan, looked for VOCs in 79 period products sold in the US including 22 kinds of tampons as well as pads, wipes, sprays, powders, and moisturizers. All products contained VOCs. Organic products did not necessarily have lower levels. Researchers noted that VOCs concentrations were generally low and did no exceed health protective guidelines. They wrote, “We recommend that toxic ingredients be eliminated and all chemicals used in these products .”
Researchers also searched for compounds that could disrupt hormones. These compounds, such as phthalates which increase plastic’s flexibility, might have made it into tampons in the manufacturing process. A 2020 study sampled 12 tampons and found phthalates in all of them. The researchers found phthalates in all tampons, despite the fact that they were below the threshold for toxic skin effects. However, they did not know the rates of absorption through the vagina and vulva. They identified tampons, as well as other menstrual products, as “an important source for chemical exposure in women .””.
To better understand whether a given chemical poses a health risk, researchers study exposure routes, the pathways through which a chemical can enter the body and travel to different organs. There are three main routes into the body that chemicals can enter: ingestion, breathing, and direct contact with skin. “The skin is designed to protect the body, and the general assumption is that not many things are able to go through the skin,” says Oddny Ragnarsdottir, a Ph.D. student at the University of Birmingham who studies dermal absorption of polyfluoroalkyl substances, or PFAS. Tampons do not sit flush against the skin, but rather fit snugly within the vagina.
Research into vaginal drug delivery has shown the vaginal canal provides a favorable environment for chemical absorption as well as circulation. The canal is full of lymphatic vessels and arteries. Vaginal mucus can stick to the vaginal wall, which can cause it to hold some molecules for a long period of time. This can stimulate absorption. The vaginal environment is dynamic and can change over time. The properties that aid absorption, such as temperature, pH level, mucus production and thickness of the vaginal wall, can vary depending on an individual’s age, health, and their menstrual cycle.
Scientists are challenged by this ever-changing environment. They want to know exactly what happens to a Tampon when it’s placed in the vagina, and how much is absorbed by the body. Researchers have two options when it comes to clinical research. In vivo, which is Latin for “in a living organ”, is the first option. This involves studying animals due to ethical and technical complications associated with conducting research on humans. In vitro–Latin is the preferred method for researchers in this field. This allows them to focus on specific bodily conditions and minimize the distractions that can occur in an organism.
One such study was done by Leonardo Pantoja of Middlesex University in London. Pantoja’s team used a setup called the “Syngina” to identify release of microplastics from tampons. The Syngina releases a saline solution at the average rate of menstrual flow until a tampon leaks; manufacturers have used the apparatus since the 1980s to test tampons’ absorbency. The results of Pantoja’s study, published in 2021, found billions of nanoplastic particles released from tampons that would be in contact with the vaginal wall. Pantoja explained that many tampons do not have woven fibers, which facilitates the release of nanoplastics. Pantoja believes that his study may have underestimated microplastics release due to differences in friction and vaginal pressure. Pantoja explained that his team was careful to focus on the most benign conditions possible in order to minimize the potential health consequences of their findings.
Researchers can also conduct epidemiological studies to gather data on adverse health effects. Kioumourtzoglou co-authored an academic article that found higher levels of mercury in the blood of tampon users, using data from the BioCycle Study. The BioCycle study–a longitudinal cohort study conducted at the University of Buffalo in the 2000s–was not designed to examine the effects of tampon use, but instead followed 250 women for two menstrual cycles to understand the relationship between hormone levels and oxidative stress, a state of chemical imbalance that can eventually lead to disease. Kioumourtzoglou, along with her co-authors, had access to the data. They looked for a correlation between participants’ tampon usage and blood levels of heavy metals.
There were no statistically significant results about mercury and other metals. However, Kioumourtzoglou explained how the very small sample size may have contributed to this.
Like other studies, this one had its limitations. Participants were asked to provide details about their tampon usage. The BioCycle study did not test participants for glyphosate. This left Kioumourtzoglou with no answer to her question. Kioumourtzoglou said that the study could be used to attract funding for future research if it found an association between reported tampon usage and oxidative stress, even though it isn’t statistically significant.
Recently, she and team of researchers received $35,000 for a small pilot study to analyze popular brands of tampons for the presence of certain pesticides and metals. After determining the concentrations of these contaminants in the products, the team will place them in samples of the menstrual blood of study volunteers. Kioumourtzoglou explained that the goal is to determine if any potentially dangerous chemicals leach from the tampon into surrounding blood.
She hopes that the larger community of scientists will also continue to study menstrual products. She said that the more people who work on it, the better .”
Women and teenage girls need access to period products, according to public health experts who have sought to draw attention to period poverty–a term used to describe the inability to afford or otherwise access menstrual products. Globally, period poverty, combined with stigma associating periods with uncleanliness, has caused youth to miss school, and it has also kept adults from fully participating in the workforce.
Stigma could also have an impact on the health care advice that doctors and nurses give patients in the clinic. Winkler, a professor at Central European University, stated that some health care professionals are not adequately trained in the substantive issues. They might not be able to listen to their patients’ concerns. Winkler stated, “People are constantly being told it’s all in their heads.” She said that better sex education could help with menstrual literacy. This will allow women to make informed, autonomous decisions about their bodies.
But comprehensive sex education may be insufficient, considering the murkiness around tampon ingredients. These and other menstrual products are regulated by the FDA as medical devices. There is little oversight from government regarding ingredient disclosure. As of 2022, New York is the only state in the US that requires manufacturers to list all ingredients in period products on the packaging. (Although the New York law only applies to products sold within the state, the rule appears to have a ripple effect on products sold in other states.) Pantoja explained, however, that even though ingredient disclosure is required, the meanings of terms such as “organic” and “pure” do not have to be standardized.
This summer’s viral TikTok on titanium dioxide in tampons focused on the brand This is L., which was acquired by Procter and Gamble in 2019. The tampons from This is L. are made with organic cotton and the company’s marketing promises a simple product. Nothing more. Period.” On Aug. 31, consumers filed a class action suit against This is L., for what they see as misleading marketing. P&G did no respond to comments or questions about when, how and why titanium dioxide is used for tampon production.
A variety of products have gained popularity as alternatives to single-use pads and tampons, including menstrual cups or period underwear made with moisture-wicking fabric. These products aren’t perfect, however, and there are issues with brand transparency as well as regulation. The FDA regulates menstrual cups as medical devices. This means that the constitutive ingredients of medical-grade silicone are not required to be listed. They have gotten lodged in women’s uteruses and been linked to toxic shock syndrome (though a 2019 study found only 25 reports of adverse effects out of more than 1,100 menstrual cup users).
Knix Wear, a brand of period underwear, is facing a class action lawsuit, with consumers alleging that the presence of PFAS forever chemicals betrays the underwear’s marketing. Another brand, Thinx, is reportedly settling a similar lawsuit.
For women shopping in the grocery store’s feminine hygiene aisle, it can be difficult to balance cost, chemicals and environmental sustainability with comfort. Winkler said that it’s important .”
to be able to make these choices for yourself.
Colleen is a writer and educator from New York City. Her work has appeared in The Diplomat Foreign policy New Lines Magazine ,, The Washington Post , and other publications. Follow her on Twitter @colleenwood_.
The author of 5 books, 3 of which are New York Times bestsellers. I’ve been published in more than 100 newspapers and magazines and am a frequent commentator on NPR.