The science behind the scar: What’s really in our period products

By Ruby Raut, founder and CEO, WUKA

Over the past year, headlines about “toxic period products” have been hard to ignore. Stories about PFAS, heavy metals, and hormone disruptors in pads, tampons, and underwear have sparked global concern, and for good reason. But behind the fear, there’s a scientific story worth understanding.

At the recent House of Lords event, “Have We Reached the Tipping Point for Toxic Period Products?”, researchers and policymakers came together to separate fact from panic. The truth is more nuanced: yes, chemicals and metals are present in some menstrual products, but understanding how much, where they come from, and what that means for our health is key to driving change that’s informed, not sensational.

What Scientists Have Found So Far

Dr Kathrin Schilling, an environmental health scientist at Columbia University, shared new research that tested 16 metals in menstrual products, including arsenic, cadmium, lead, and antimony, all known toxic substances linked to long-term health effects such as cardiovascular disease, kidney problems, and hormonal disruption.

The findings were striking:

• Non-organic products showed higher levels of lead and cadmium than organic ones.
• Some reusable and single-use products exceeded 30,000 nanograms per gram (ng/g) of antimony, a toxic metal commonly used in plastics manufacturing.
• Lead levels varied dramatically, some products contained 100× more than others.

To put this in perspective, even very small doses of lead can cause harm. The World Health Organization confirms there is no safe level of lead exposure. Chronic, low-level contact can gradually affect the nervous system and fertility. The same applies to arsenic, where countries have tightened drinking water limits from 10 µg/L to as low as 1 µg/L after learning that long-term exposure causes disease.

So while the numbers in menstrual products might sound tiny, what matters most is frequency and route of exposure. Menstrual products are used regularly and in contact with one of the body’s most absorbent tissues — the vaginal wall — where absorption is estimated to be 10–80× higher than through skin. Over decades of use, even low concentrations can add up.

Understanding PFAS — The “Forever Chemicals”

Alongside metals, PFAS (per- and polyfluoroalkyl substances) have become another major concern. These synthetic compounds are used for absorbency and stain resistance — but they don’t break down easily, earning the name “forever chemicals.”

They accumulate in soil, water, and the human body, and have been linked to reproductive issues, thyroid disease, and immune dysfunction. California recently became the first state to ban PFAS in menstrual products, while New York is pushing for broader restrictions that include heavy metals and hormone disruptors.

These international shifts signal a clear message: the world is moving towards stricter, transparency-first regulation — something the UK could soon follow.

Why It Matters for Our Bodies

It’s important to remember that our world is already filled with background exposure, from air pollution, processed food, and household plastics. We all live in a chemically complex environment. The key isn’t to fear every product but to understand which exposures matter most and how to minimise them.

Menstrual products are unique because of their intimate and repeated contact with the body. Even trace chemicals can bypass the body’s natural detox systems when absorbed vaginally. This doesn’t mean every product is dangerous, but it underscores why regular, independent testing and clear ingredient disclosure are essential.

Internal vs. External Exposure:  Why It Makes a Difference

One of the least understood parts of this debate is the difference between internal and external products. A pad or period underwear sits on the skin; it can only transfer chemicals through surface contact. But products like tampons or menstrual cups are inserted directly into the vagina, an environment that absorbs substances 10–80 times more efficiently than normal skin.

That’s because the vaginal wall is highly vascular, full of small blood vessels, and it bypasses the liver, the organ that usually filters and detoxifies harmful substances. So when a chemical is absorbed vaginally, it goes straight into the bloodstream.

Yet, most testing and regulation still treat all menstrual products as if exposure happens through skin contact. There’s very little research separating the risk profiles of internal (tampons, cups, discs) versus external (pads, underwear) products. That’s why scientists like Dr Schilling emphasised the need for new safety standards that actually reflect how the body interacts with these materials, not just how a fabric performs in a laboratory test.

How Responsible Brands Are Responding

Some brands are already ahead of regulation.

At WUKA, we take this responsibility seriously. We are one of the very few period underwear brands with no PFAS detected in our products. Every batch is tested rigorously, both at source (in China) and again in the UK by Eurofins laboratories, an independent global testing agency.

We also screen for toxic chemicals, metals, and harmful finishes, ensuring that what touches your body is as safe as it is sustainable. As a founder, I always remind our team: I use our products myself. If I wouldn’t wear it, I wouldn’t make it for anyone else.

Our philosophy is simple,  transparency builds trust. Consumers shouldn’t need a chemistry degree to choose a safe period product.

The Path Ahead

The science is clear: menstrual product safety deserves the same rigour as drinking water, cosmetics, or food. But we can also take heart, awareness is growing, data is expanding, and governments are beginning to act.

As policymakers push for international standards (through bodies like the ISO TC338 on menstrual products), and as responsible brands lead by example, the future of menstrual care looks safer, smarter, and far more transparent than the past.

This isn’t just about fear of toxins, it’s about empowering everyone who menstruates with knowledge and choice. Because understanding the science is the first step toward changing it.

Find out more about WUKA at wuka.co.uk