Is merino wool a safer choice than synthetic for activewear?
Yes. Merino wool doesn't shed microplastics or need chemical finishes.
What's actually in it
Merino wool is a natural fiber from fine-wool sheep. It breathes, wicks moisture, and resists odor naturally (no antimicrobial treatment needed). It doesn't shed microplastics and doesn't need flame retardants to pass fire tests.
What the research says
A 2025 study in Sci Total Environ showed sweat pulls chemicals out of synthetic kids' textiles. Merino doesn't carry those chemicals. A 2025 screening study found synthetic textiles among heavy sources of flame retardants and PFAS.
Merino works for base layers, socks, and light workout tops. For very heavy sweating, a merino blend with nylon for durability is a practical compromise.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Sweat-amplified dermal transfer of PFAS and OPEs. | Sci Total Environ | 2025 |
| Chemical signatures for household consumer products. | Environ Sci Technol | 2025 |
What to use instead
Browse our vetted, non-toxic alternatives. Every product is third-party certified.
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