The question sounds alarmist until you look at what is actually in most yoga pants.
Yoga pants are almost universally made from synthetic fabrics: polyester, nylon, spandex, or blends of all three. For women building a non toxic activewear wardrobe, understanding what is in those fabrics is the starting point. Those fibers are petroleum-derived plastics, frequently treated with performance finishes that introduce a second layer of chemical inputs, worn pressed tightly against skin for hours at a time in conditions that favor chemical migration and microfiber release.
What the Lululemon Investigation Revealed
In April 2026, the Texas Attorney General issued a Civil Investigative Demand to Lululemon, one of the most recognizable yoga pants brands in the world, investigating whether the company misled consumers about the potential presence of PFAS in activewear marketed to health-conscious buyers. Lululemon acknowledged that PFAS had been used in its durable water repellent products and stated it had phased them out in early 2024. A separate class action lawsuit filed in California alleged the company misled consumers through sustainability-focused advertising while its clothing contained PFAS.
The significance of the Lululemon case is not that one brand got caught. It is what the case confirmed: that PFAS chemistry has been routine in the activewear category, including in brands positioning themselves as wellness products. If it happened at Lululemon, the assumption that other synthetic activewear brands are categorically different requires evidence, not just marketing language.
PFAS in Yoga Pants: What It Means
PFAS, per- and polyfluoroalkyl substances, are used in durable water repellent coatings and stain-resistance treatments applied to many synthetic garments. They do not break down in the environment or in the human body. The EPA has linked PFAS exposure to thyroid disruption, immune suppression, increased cholesterol, and elevated cancer risk based on human epidemiological data.
Yoga pants with DWR coatings or stain-resistance finishes, marketed features in many premium synthetic brands, are the most likely to carry PFAS. The fiber label on a garment does not disclose whether these finishes have been applied. A garment listed as 87% nylon, 13% spandex tells you nothing about what chemical treatments the fabric received before it reached you.
Microplastics: The Shedding That Happens During Wear
Synthetic yoga pants shed microplastic fibers during wear and washing. Napper and Thompson (2016), writing in Marine Pollution Bulletin, documented consistent microfiber shedding from synthetic fabrics under standard washing conditions. Research has also documented shedding during wear, through friction and movement against the skin.
In yoga specifically, where poses involve sustained compression, twisting, and extended skin contact with the fabric, the mechanical conditions for fiber shedding are present throughout the practice. The fibers shed during wear settle on skin and enter the immediate environment. Leslie et al. (2022), in Environment International, detected microplastic particles in human blood, confirming systemic absorption is occurring across the general population.
Skin Absorption During Exercise
Exercise changes the skin's absorption dynamics. Elevated body temperature, increased blood flow to the surface, and open pores during sweating create conditions that are more favorable for transdermal absorption of chemicals and particles than resting conditions. A 2021 analysis in Sustainability examined microplastic absorption potential through skin and noted that exercise-specific conditions increase absorption likelihood compared to rest.
This matters for yoga pants in particular because of how they are worn: full-leg coverage, sustained body contact, and typically worn for 60 to 90 minutes or more in a heated or active setting. The exposure duration and skin coverage are both higher than most other garment categories.
What Lower-Risk Yoga Pants Look Like
The fiber is the starting point. A yoga pant made from TENCEL Lyocell rather than polyester or nylon begins from a different chemical baseline. TENCEL is a cellulosic fiber, not a petroleum-derived polymer. It does not shed plastic microfibers in the way synthetic fabrics do. Its moisture management is structural, absorbing into the fiber's core rather than wicking along the surface, which supports thermoregulation without requiring chemical odor-control treatments.
Kaplan et al. (2014), in Fibers and Polymers, documented TENCEL's performance advantages in moisture management and thermal comfort in active wear. The fiber carries OEKO-TEX Standard 100 and EU Ecolabel certification, meaning it has been independently tested for harmful substances.
Bellissima's Sempre Leggings are 92% TENCEL Lyocell and 8% spandex. The spandex content is disclosed because partial ingredient transparency is not the standard here.
The Honest Answer
Are yoga pants toxic? The honest answer is: it depends on what they are made of, what chemical finishes were applied, and how that information has or has not been disclosed to the person wearing them.
For most yoga pants currently on the market, made from synthetic fibers and sold by brands that until recently used PFAS chemistry as standard practice, the chemicals present are real, the exposure pathway is direct, and the buyer has typically been given no way to know. For the full picture on how this connects to hormones, whether activewear affects your hormones covers the endocrine disruption evidence specifically. For the broader health question, whether leggings are bad for your health covers more ground. And for the full chemical breakdown, toxic chemicals in workout clothes and the non-toxic activewear buying guide cover what to look for and avoid.
Sources
Texas Attorney General. (2026, April 13). Attorney General Ken Paxton Launches Investigation into Lululemon Over Potential Presence of Toxic Forever Chemicals in Activewear. texasattorneygeneral.gov.
U.S. Environmental Protection Agency. (2024). Our Current Understanding of the Human Health and Environmental Risks of PFAS. EPA.gov.
Napper, I.E., and Thompson, R.C. (2016). Release of synthetic microplastic plastic fibres from domestic washing machines. Marine Pollution Bulletin, 112(1-2).
Leslie, H.A., et al. (2022). Discovery and quantification of plastic particle pollution in human blood. Environment International, 163.
Kaplan, S., et al. (2014). Thermal comfort of lyocell and other fibers in active wear. Fibers and Polymers, 15(6).
