Tampons are made primarily of cotton, rayon, or a blend of the two, compressed into an absorbent plug and wrapped in a thin cover layer. That much has been on packaging for decades. What has drawn more attention lately is what else turns up when researchers put tampons under a mass spectrometer: trace metals including lead and cadmium, volatile organic compounds, phthalates, and fragments of fragrances, all at low but measurable levels. Whether any of that actually matters for health is a separate and more complicated question than the headlines suggest.
The Core Fibers
The absorbent body of a modern tampon is made from cotton fibers, rayon fibers, or a combination of both. Cotton comes from the cotton plant and arrives as short, naturally crimped fibers. Rayon is a semi-synthetic fiber derived from wood pulp cellulose, processed through chemical steps that dissolve the pulp and regenerate it into soft, highly absorbent strands. Most major-brand tampons in the United States use a cotton-rayon blend, because rayon’s absorbency and cotton’s structural integrity complement each other.
A thin cover wraps the compressed fiber core. Some covers are made of nonwoven fleece (essentially a mesh of bonded fibers), while others use a perforated film. A randomized study comparing the two cover types found no differences in vaginal microflora or epithelial integrity on colposcopy, suggesting the cover material is biologically inert under normal use conditions.1PubMed Central. A prospective, randomized, double-blind study of vaginal microflora and epithelium in women using a tampon with an apertured film cover compared with those in women using a commercial tampon with a cover of nonwoven fleece The string is typically polyester or cotton. Plastic applicators, when present, are usually polyethylene or polypropylene.
Tampons sold as “100% organic cotton” skip the rayon entirely and use cotton grown without synthetic pesticides or fertilizers. Whether that distinction makes a meaningful health difference is something we will come back to.
Metals Found in Tampons
A 2024 study that tested 30 tampons from 14 brands found measurable concentrations of all 16 metals the researchers looked for. Lead was among the most elevated, with a geometric mean of 120 nanograms per gram. Cadmium averaged about 6.74 ng/g, and arsenic came in around 2.56 ng/g.2PubMed Central. Tampons as a source of exposure to metal(loid)s That study made international headlines, in part because “lead in tampons” is an alarming phrase regardless of dose.
A follow-up toxicological risk assessment confirmed the presence of metals, including arsenic, cadmium, and lead at trace levels, but reached a different conclusion about what the numbers mean. The researchers calculated margins of safety for each metal. For lead, the worst-case margin of safety was about 7; for cadmium, about 24; for arsenic, about 53. All margins exceeded 1, which is the threshold below which regulators start worrying. The study concluded that the metals in the 11 tampon products it tested did not raise toxicological concerns.3Toxicological Sciences. Do metals in tampons pose a health risk? A toxicological risk assessment study
The gap between “metals are present” and “metals are dangerous” is where most of the confusion lives. Metals exist in soil, water, and food. Cotton plants pull trace metals from the ground they grow in, and rayon processing uses chemicals that can introduce additional traces. The question is whether those metals leach out of the tampon fibers and get absorbed through vaginal tissue in quantities large enough to matter.
Do Those Metals Actually Get Into Your Body?
Detecting metals in a tampon fiber is not the same as proving those metals enter your bloodstream. A tampon sits in the vaginal canal for several hours, but the metals are bound within fiber matrices, and the question is how much actually dissolves into vaginal and menstrual fluids under real conditions.
A quantitative risk assessment that simulated vaginal and menstrual pH conditions found that metal leaching was minimal. Under physiologically relevant conditions, the amounts of metal released were at or near analytical detection limits. The margins of safety were enormous, ranging from roughly 97,000 for cobalt to about 64.5 million for chromium. Even in a deliberately extreme scenario where metal concentrations were assumed to be 10,000 times higher than what was actually measured, all margins of safety still exceeded 1, with cadmium the tightest at about 24.4Environmental Advances. Quantitative risk assessment framework for metal exposure from tampon use
Another leaching study put lifetime tampon use in perspective. Over an estimated 10,000 tampons across 40 reproductive years, cumulative exposure to arsenic, cadmium, and lead from tampons would be equivalent to drinking roughly 6 to 27 liters of water at the EPA’s maximum contaminant levels for those metals. That is a meaningful comparison because it is a small amount of water spread across four decades of use.5AJOG Global Reports. In vitro metal leaching from tampons under simulated vaginal and menstrual pH conditions
The vagina can absorb certain compounds efficiently. Some steroids, for example, are more bioavailable through vaginal absorption than through oral dosing because they skip the liver’s first-pass metabolism.6PubMed. Absorption from the vagina That is why the question of metal leaching from tampons deserves serious investigation rather than dismissal. But the leaching data so far suggest that the metals stay mostly locked in the fibers rather than dissolving into surrounding fluids in meaningful quantities.
Chemical Contaminants Beyond Metals
Metals get the headlines, but tampons and other menstrual products contain a wider range of trace chemicals. A systematic review of the literature found that phthalates, volatile organic compounds, parabens, environmental phenols, fragrance chemicals, dioxins, and dioxin-like compounds have all been detected in menstrual products.7PubMed. Chemicals in menstrual products: A systematic review
A detailed extractables-and-leachables investigation of menstrual and intimate care products identified 55 unique chemicals in the products tested, including phthalates, siloxanes, VOCs, fragrances, and plastic additives. The reassuring part: when the researchers moved from testing what could be chemically extracted under aggressive lab conditions to testing what actually leached out under simulated use, about 65% of those chemicals disappeared. Of the 55 identified, only 19 showed up in leachable form, and those were primarily fragrances, phthalates, and plastic additives.8PubMed. Chemical characterization of menstrual and intimate care products: An extractables & leachables investigation That distinction between what a product contains and what it releases matters enormously for actual exposure.
Dioxins
Dioxins have been a concern since the 1990s, when environmental groups raised alarms about chlorine bleaching of wood pulp used in rayon production. Modern bleaching processes have largely shifted to chlorine-free or elemental-chlorine-free methods, which dramatically reduced dioxin levels. An exposure assessment that analyzed four brands of tampons found no 2,3,7,8-tetrachlorodibenzo-p-dioxin (the most toxic form) in any product. Other dioxin variants were present at detectable levels, but the estimated exposure from tampons was roughly 13,000 to 240,000 times lower than typical dietary dioxin exposure.9PubMed Central. Exposure assessment to dioxins from the use of tampons and diapers In other words, the dioxin you encounter through food dwarfs anything a tampon contributes.
PFAS
Per- and polyfluoroalkyl substances, the so-called “forever chemicals,” are a newer concern. A study testing reusable feminine hygiene products found that period underwear and reusable pads had the highest rates of intentional PFAS use, at 33% and 25% of products respectively. When products were analyzed for specific PFAS compounds, every extracted product tested positive for at least some.10Environmental Science & Technology Letters. Per- and Polyfluoroalkyl Substances in Reusable Feminine Hygiene Products A separate study found PFAS in disposable products too, with sanitary pads averaging about 52 ng/g and menstrual cups around 21 ng/g.11PubMed. Per- and Polyfluoroalkyl Substances in Personal Hygiene Products: The Implications for Human Exposure and Emission to the Environment PFAS research in menstrual products is still in early stages, and regulators have not set specific limits for PFAS in these products. The compounds are used for moisture resistance and stain-proofing, which explains why reusable products with textile layers tend to have higher levels.
What “Organic” and “Natural” Labels Do and Don’t Tell You
You might reasonably assume that organic tampons avoid the chemical contamination issues described above. The evidence is less clear-cut. A survey of feminine hygiene products sold in the US found that products labeled “organic,” “natural,” or “for sensitive skin” did not consistently have lower concentrations of volatile organic compounds than conventional products.12PubMed Central. Volatile organic compounds in feminine hygiene products sold in the US market: A survey of products and health risks
For metals, the picture is similarly complicated. The 2024 metals study found that organic tampons did not categorically contain fewer metals than conventional ones. Cotton picks up whatever is in the soil it was grown in, and “organic” certification governs pesticide and fertilizer use during farming, not the metal content of the harvested fiber. A field irrigated with water containing trace lead will produce cotton with trace lead whether or not synthetic pesticides were applied.
The dioxin data tell a similar story. Minimal differences in dioxin concentrations appeared between 100% cotton products and cotton/pulp blends.9PubMed Central. Exposure assessment to dioxins from the use of tampons and diapers This makes sense given that modern processing methods have reduced dioxin contamination across the board, regardless of whether the raw material is organic cotton or conventionally processed rayon.
None of this means organic tampons are a scam. Organic farming has environmental benefits, and some people prefer to minimize pesticide residues on materials that contact mucous membranes. But if you are buying organic tampons specifically because you believe they are free from trace metals or chemical contaminants, the data do not reliably support that expectation. The label tells you about how the cotton was farmed. It tells you little about what else ended up in the finished product.
Tampons and Toxic Shock Syndrome
One of the most persistent questions about tampon composition is whether the fiber type affects the risk of toxic shock syndrome. TSS is caused by toxins produced by Staphylococcus aureus bacteria, and a wave of cases in the early 1980s was linked to a specific super-absorbent tampon (Rely, which used carboxymethylcellulose and polyester foam). That product was pulled from the market, but concern about fiber composition lingered.
Research since then has been fairly consistent. A study comparing cotton-only and cotton/rayon tampons found that under both oversaturated and 50%-saturated conditions, cotton tampons produced the same amount of or more TSS toxin (TSST-1) than cotton/rayon blends.13Oxford Academic (The Journal of Infectious Diseases). Comparison of cotton and cotton/rayon tampons for effect on production of toxic shock syndrome toxin A separate study confirmed that neither cotton nor rayon consistently increased toxin production, and there were no significant differences between them. Importantly, a tampon made from carboxymethylcellulose and polyester foam did dramatically increase toxin output, pointing to the now-discontinued materials as the real culprit.14The Journal of Infectious Diseases. Effect of Tampon Composition on Production of Toxic Shock Syndrome Toxin-l by Staphylococcus aureus In Vitro
More recent in vitro testing of currently marketed tampons found that most reduced S. aureus growth and TSST-1 production, though differences existed between brands and compositions. Tampons that had been physically pulled apart (destructured) supported more bacterial growth than intact ones, a reminder that the tampon’s physical structure matters alongside its chemistry.15PubMed Central. Impact of Currently Marketed Tampons and Menstrual Cups on Staphylococcus aureus Growth and Toxic Shock Syndrome Toxin 1 Production In Vitro
The practical takeaway is that current cotton and rayon tampons are not meaningfully different from each other in terms of TSS risk, and the materials that genuinely amplified TSS toxin production have not been used in tampons for over 40 years. Claims that all-cotton tampons are “safer” for TSS do not hold up in the lab data.
How Tampons Are Regulated
The regulatory landscape varies by country and can be confusing. In the United States, tampons are classified as Class II medical devices by the FDA, which means manufacturers must demonstrate safety and effectiveness through a premarket notification process (510(k)). The European Union treats them as general consumer products, and South Korea classifies them as quasi-drugs. Despite these different regulatory categories, the basic safety requirements are broadly similar across all three systems.16PubMed. Comparative study of feminine hygiene product regulations in Korea, the European Union, and the United States
In the US, the FDA requires that tampons meet biocompatibility standards and absorbency labeling requirements (the familiar “regular,” “super,” “super plus” designations correspond to standardized absorbency ranges measured in grams). What the FDA does not require is full ingredient disclosure of processing chemicals, fragrance components, or trace contaminants. A tampon box might say “rayon and cotton” without mentioning anything about the adhesives, dyes, or finishing agents used during manufacturing. Legislative efforts in several US states have pushed for more detailed ingredient labeling, and some brands have voluntarily started listing components, but it remains uneven.
The medical-device classification does mean that tampons undergo more regulatory scrutiny than, say, a cotton T-shirt. Manufacturers must comply with good manufacturing practices and report adverse events. But “medical device” also sets certain expectations in consumers’ minds that the product has been exhaustively tested for trace contaminants, and the reality is more modest than that. The FDA’s framework focuses on acute risks like TSS and physical safety, not on chronic low-level chemical exposure from trace contaminants in fiber matrices.
Tampons Through the Ages
Modern tampons feel like a recent invention, but the concept of an internal menstrual absorbent is ancient. Egyptian women used soft papyrus as early as the 15th century BC. Hippocrates described lint wrapped around small pieces of wood used by Greek women in the 5th century BC. Ancient Romans used wool. Japanese women used paper, Indonesian women used vegetable fibers, and women in equatorial Africa used grass and sponges. The commercial tampon as we know it, a compressed fiber plug with a removal string and optional applicator, arrived in the 1930s. Today’s tampon would be unrecognizable to someone using papyrus, but the underlying idea of inserting an absorbent material has remained remarkably consistent for thousands of years.
Choosing a Tampon Based on What the Science Actually Shows
If you have read this far, you might feel caught between two competing messages: tampons contain trace amounts of metals and chemicals, but the amounts appear too small to cause harm based on current evidence. That tension is real, and it reflects where the science stands. The detection studies are solid. The risk assessments so far are reassuring. What is missing is long-term epidemiological data tracking whether decades of tampon use correlate with any health outcomes linked to chronic low-level metal or chemical exposure. That kind of study takes years and has not been completed.
In the meantime, a few practical considerations are supported by the evidence:
- Fiber type: Cotton and rayon are roughly equivalent in terms of TSS risk and contaminant profiles. Pick based on comfort and absorbency preference, not fear of one fiber over the other.
- Organic labels: These reflect farming practices, not contaminant-free guarantees. If organic matters to you for environmental reasons, that is a valid choice, but do not expect it to eliminate trace metals or VOCs from the finished product.
- Absorbency: Use the lowest absorbency that works for your flow. This remains the single most evidence-backed step for reducing TSS risk, and it has nothing to do with which chemicals are in the fiber.
- Fragrance: Scented tampons introduce additional fragrance chemicals into a mucous membrane environment. Given that fragrances were among the compounds that did leach under simulated use conditions, unscented products are a straightforward way to reduce one category of chemical exposure.
Menstrual cups, discs, and period underwear are sometimes positioned as “chemical-free” alternatives, but the PFAS data suggest reusable textile products carry their own contaminant profiles. No menstrual product exists in a chemical vacuum. The question with every product is not whether trace chemicals are present, because they almost certainly are, but whether the exposure levels fall within ranges that your body handles without difficulty. For tampons, the current weight of evidence says they do.