A 2026 laboratory study found oestrogenic activity in extracts from 8 of 18 tampon products tested. In plain language, something in those extracts activated oestrogen receptors in a cell test. It is a finding worth investigating, but the study did not test whether using tampons changes hormone levels or affects health.
Here is what the researchers actually measured, where the limits are and what the findings mean if you use tampons.
Key takeaways
- Researchers tested 18 tampon products representing 13 brands. Extracts from 8 products showed detectable oestrogenic activity in a laboratory cell test.
- Products labelled organic or cotton-based and products containing synthetic materials were represented among the positive results. The small sample cannot tell us which type is safer.
- The study did not measure chemical absorption through vaginal tissue, hormone levels in people or health outcomes.
- If tampons suit you, this one study does not establish a reason to stop using them. It does support further research and clearer information about product materials.
What did the tampon study find?
Researchers at the University of Otago tested 18 different combinations of tampon brand, product line and absorbency. These represented 13 brands. Extracts from 8 of the 18 products produced a detectable response in a test designed to measure oestrogenic activity. The other 10 did not produce a detectable response under the conditions tested.
Oestrogenic activity means that a sample activates oestrogen receptors in the test system. It does not tell us which individual chemical produced the response, how much would enter the body during tampon use or whether it would change a person's hormones.
How were the products tested?
The researchers soaked tampon material in a water–ethanol solution for four hours. They then processed and concentrated the extracts before applying them to a laboratory cell assay called T47D-luc. The cells produce a measurable signal when their oestrogen receptors are activated.
Four hours was chosen to approximate a typical wear period, but the solvent and extraction process do not reproduce conditions inside the vagina. The main process included sonication, which can increase the release of chemicals. In a separate check, one product that tested positive still showed activity without sonication.
This makes the test useful for flagging a question about product chemistry. It cannot show what dose a person would absorb during ordinary use. The study was funded by InsituGen and Organic Initiative. Several authors disclosed employment or financial interests in InsituGen; the paper says Organic Initiative had no input into the study design, analysis or manuscript.
Which chemicals might be involved?
The researchers used mass spectrometry to compare extracts from one product with detectable activity and one without. They identified, or tentatively identified, a range of compounds, including plasticisers, surfactants and fragrance-related compounds. Some were known or suspected endocrine-disrupting chemicals, including certain phthalates and alkylphenol-related compounds.
That comparison involved two products. It did not establish a complete chemical profile for every tampon tested or prove which compound caused the cell response. Some compounds were detected in both products.
Were organic tampons affected?
Yes. Of 12 products the researchers grouped as organic or cotton-labelled, 4 showed detectable activity. Four of the 6 products grouped as synthetic or rayon-blend also showed activity.
Those figures describe this particular group of products, not the overall rate for organic or synthetic tampons. An organic or cotton label describes part of the product, but does not by itself tell you everything about the finished tampon or how it performs in this test.
Does this mean tampons disrupt your hormones?
The study cannot answer that question. It tested tampon extracts on cells, not people using tampons. It did not measure absorption through vaginal tissue, blood levels, menstrual changes, fertility or other health outcomes.
There is a real difference between finding a response in a sensitive laboratory test and showing a meaningful effect in the body. Further work would need to examine exposure during actual use and whether that exposure has any health significance. The researchers described the activity they detected as low, while noting that its relevance to human health remains unclear.
What about the research on metals in tampons?
A separate 2024 study measured 16 metals and metalloids across 30 tampons from 14 brands. It measured what was present in the tampon materials, but did not establish how much could leave a tampon during use or enter the bloodstream. We discuss that research in our article on metals in tampons.
In 2026, US Food and Drug Administration researchers examined metal release from 11 tampon products sold in the United States and assessed possible exposure. They found negligible toxicological concern from the metals under their assessment. That finding addresses metals in the products tested; it does not resolve the separate question of oestrogenic activity raised by the Otago study.
Are tampons regulated in Australia?
Yes. Tampons sold in Australia must meet the applicable requirements under Therapeutic Goods Order 103 and Australian Standard AS 2869:2022. These include requirements for materials, packaging and labelling, absorbency, microbial content and withdrawal cord strength.
Tampons are exempt from listing on the Australian Register of Therapeutic Goods, so they are not individually assessed by the Therapeutic Goods Administration before supply. They still have to comply with the relevant standard. Current requirements do not mean every question about low-level chemical exposure has already been answered.
Should you change the period products you use?
If tampons work well for you, this study alone does not show that you need to stop using them. Follow the instructions on the pack, change tampons regularly and never leave one in for more than eight hours. Toxic shock syndrome is rare but serious; our TSS guide explains the symptoms and when to seek urgent care.
If you would prefer another option, menstrual cups, discs, sea sponges and cloth pads give you different choices for comfort, use and reusability. The Otago study did not test these products, so it cannot tell us that one of them is safer than a tampon.
You can compare a wider range of period products in our Menstrual Products Comparison Hub or download the free Period Care Comparison Guide. The guide includes products we do not stock, such as period underwear, so you can compare the options on their merits.
What should you take away from the research?
Some tampon extracts activated oestrogen receptors in a laboratory test. That finding deserves follow-up, including research on what people are actually exposed to during use. It does not establish that tampons disrupt hormones or cause illness.
You can keep using the products that suit your body and preferences while asking for better material transparency and research. If you have persistent symptoms or concerns about your hormone health, speak with a qualified healthcare professional.
Sources
- Sutherland ES et al. Estrogenic Activity in Tampon Products. Journal of the Endocrine Society, 2026.
- Shearston JA et al. Tampons as a source of exposure to metal(loid)s. Environment International, 2024.
- Jin Y et al. Do metals in tampons pose a health risk? A toxicological risk assessment study. Toxicological Sciences, 2026.
- Therapeutic Goods Administration. Manufacturing or supplying tampons.
- Healthdirect Australia. Toxic shock syndrome.
This article provides general health information and does not replace personalised medical advice.