The Truth About Polyester: Cancer, Chemicals, and the Cost of Athleisure

Like most of Gen Z, I basically live in athleisure. Leggings are my second skin — from early-morning coffee runs to late-night brainstorms, from hot yoga to Whole Foods. But recently, I came across something online that made me stop scrolling. It was a warning about polyester — the synthetic fabric used in most of our athletic wear — and how it might be linked to serious health risks, including cancer. I assumed it was internet fear-mongering. But the more I thought about it, the more I realized I didn’t actually know what these clothes were made of — or how they might be affecting my body. So I did what I always do when something doesn’t sit right: I researched.

What I found was honestly pretty disturbing.

Polyester is made from petroleum — the same crude oil used to produce gasoline — and it’s processed with dozens of industrial chemicals to make it stretchy, sweat-wicking, and durable. Among those chemicals? Bisphenol A (BPA), phthalates, and antimony trioxide, just to name a few. BPA and phthalates are both known endocrine disruptors, meaning they can mimic or interfere with hormones in our bodies, which plays a role in reproductive issues and, yes, cancer. Antimony, a chemical catalyst used in polyester production, has been classified as a possible human carcinogen — and studies show it can leach out of fabrics, especially when combined with heat, moisture, and friction (aka, exercise and sweat).

One study published in Environmental Science & Technology found that sweat increases the rate at which these chemicals are released and absorbed through the skin. So if you’re going commando in leggings, you might be exposing some of your most sensitive areas to carcinogenic compounds without even knowing it.

And the potential harm goes beyond hormonal or reproductive health. As someone who works in Alzheimer’s and cancer research, I was especially shaken by research showing that many of the same chemicals found in synthetic clothing are being investigated for their effects on brain health. According to the Alzheimer’s Drug Discovery Foundation, up to 10% of the thousands of chemicals used in the textile industry may be neurotoxic. Combine that with the fact that microplastics — which shed from polyester clothing every time we wash them — have now been found in human lungs, placentas, and even the bloodstream, and suddenly the wellness space feels like it’s been missing a major red flag.

But perhaps what makes this all worse is that we’re being massively overcharged for it. Polyester is incredibly cheap to make — often just a few cents per yard — yet we’re paying upwards of $100 for leggings made from it. Companies are cashing in on performancewear by branding it as “luxury wellness,” but what we’re really getting is plastic-based fabric laced with hormone disruptors. It’s the ultimate bait-and-switch — polished, aspirational marketing on the outside, and a whole lot of greenwashing and corner-cutting on the inside. Profit over people is a hard truth to swallow, especially when it’s dressed up as empowerment.

I’ll be honest — I’m not swearing off polyester completely. It makes up 90% of my current wardrobe, and throwing it all away would be both unrealistic and wasteful. But I am choosing to wear it less. I’m investing in 100% organic cotton pieces when I can — especially for sleepwear, loungewear, and anything that sits close to my skin for long periods of time. I’m layering more. I’m buying less but better. And I’m asking more from the brands I support.

Gen Z has led the charge on clean skincare, low-tox living, and mental health advocacy. It’s time we add textile awareness to the conversation. Not to create fear, but to reclaim our right to know what we’re putting on our bodies every day — and to protect the long-term health of the only bodies we’ve got.