Most leggings are made from polyester or nylon — synthetic fibers that shed microplastic particles with every wash. If you wear leggings regularly, this is worth understanding. Here’s what the research shows and what your options are.
Why Leggings Can Shed Microplastics
Leggings are one of the most washed and most worn garment categories in many wardrobes — which means they’re also one of the higher-contributing garments for microplastic release over a person’s lifetime.
The typical legging fiber composition is 70–90% polyester or nylon with 10–30% spandex/elastane for stretch. Both polyester and nylon are synthetic polymers — when their fibers break down at the tips and ends, they release tiny pieces of plastic.
The key factors that drive shedding:
Wear frequency: The more often you wear leggings, the more friction and movement-based shedding occurs.
Wash frequency: The main shedding event for synthetic fabrics is washing. Leggings that are worn frequently are also washed frequently.
Fabric construction: A tightly knit or woven structure with long fibers is more stable. Loosely knit or cut-fiber fabrics (like fleece) shed significantly more.
Age: Older leggings shed more as the surface fibers have been progressively degraded.
Which Materials Shed the Most
All synthetic fabrics shed microplastics, but some shed significantly more than others:
Acrylic sheds the highest volume of microfibers per wash of any common fabric — research from Plymouth University found acrylic released substantially more fibers per wash than polyester or nylon.
Fleece (polyester) is also a high-shedding fabric — its looped, fluffy structure has many more loose fiber ends than a tightly woven polyester.
Polyester knit (typical legging fabric) sheds at a moderate rate. Tightly knit constructions shed less than loosely knit ones.
Nylon sheds at a similar or slightly lower rate than polyester in equivalent constructions.
Spandex/Elastane contributes a small percentage of the fabric weight but is not a major shed source on its own.
How Wear and Washing Affect Shedding
Washing is the primary event. The mechanical agitation of a washing machine — water forcing through fabric, fabrics rubbing against each other, drum movement — is the main driver. A cold, gentle cycle sheds significantly fewer fibers than a hot, heavy-duty cycle.
Friction during wear matters too. High-intensity activity (running, cycling, yoga flow) creates more fiber friction than lower-intensity wear. Skin-on-fabric contact, seam rubbing, and leg-on-leg contact all contribute.
First washes shed most. New leggings often shed the most in their first few washes as loose surface fibers are released. This is why some people recommend washing new synthetics before first wear — to shed that initial load into a controlled environment (ideally with a Guppyfriend bag or similar filter).
Safer Legging Materials to Look For
Merino wool leggings: The highest-performing natural fiber alternative for leggings. Merino regulates temperature, wicks moisture, resists odor, and doesn’t shed microplastics. It’s more expensive but lasts longer and can be worn more times between washes.
Organic cotton/spandex leggings: A natural fiber blend that provides moderate stretch. Sheds natural cotton fibers rather than plastic. Less performance-oriented than polyester but fine for lower-intensity movement and everyday wear.
Certified recycled nylon: If you want synthetic performance, recycled nylon (such as ECONYL®) with bluesign® certification is a more considered choice. Same shedding behavior as virgin nylon, but sourced from post-consumer waste.
Tight-knit over loose-knit construction: When synthetic is the only practical option, favor leggings with a tighter, smoother knit rather than a textured or fluffy surface. Less surface area = less shedding.
FAQ
Do all leggings release microplastics?
Leggings made from synthetic fibers (polyester, nylon, acrylic) do. Leggings made from natural fibers (merino wool, organic cotton) shed natural fibers, not plastic. The distinction matters because plastic microfibers behave differently in the environment than natural fiber fragments.
Is there a completely shedding-free synthetic legging?
No synthetic fabric is entirely shed-free. The goal is to reduce shedding through better construction, lower-impact washing, and microfiber capture tools.
Should I throw out my polyester leggings?
No — the most sustainable choice is to use what you have. Reduce shedding by washing less often, using a Guppyfriend bag, and choosing cold gentle cycles. When it’s time to replace, consider natural fiber alternatives.
Do compression leggings shed more?
Compression fabrics are typically tightly knit by nature, which can mean slightly lower shedding than looser constructions. However, the high frequency of washing athletic wear offsets this.
Related reading: Microplastics in Clothing: What You Should Know · Fabrics That Don’t Shed Microplastics as Easily
Use Wove to compare legging fabrics. Download Wove and see how your leggings score on microplastic shedding risk.
Sources
- Plymouth University: Microfibres from Synthetic Clothing Study
- Fraunhofer Institute: Microfiber Shedding Research
- IUCN: Primary Microplastics in the Oceans
- Patagonia: Microplastics Research Summary