clean running gear. not plastic. not toxic.
notnotrunning makes women's 100% merino wool running shorts — non-toxic running shorts with no polyester, no microplastics, and no PFAS.
Women's 100% merino wool running shorts. First release — coming soon
Certified clean
every fibre, certified.
One fibre, nothing else — 100% RWS-certified Australian merino, tested to OEKO-TEX Standard 100.
rws australian merino
The merino we use is Australian, certified to the Responsible Wool Standard — for sheep welfare, responsible land management, and chain-of-custody from grower to yarn.
oeko-tex standard 100
The merino yarn is tested to OEKO-TEX Standard 100 — free from harmful substances. No PFAS, no formaldehyde, no heavy metals, no banned azo dyes.
Why no polyester
running was supposed to be healthy.the gear shouldn't undo that.
Most performance shorts on the market are polyester, nylon, or elastane — petroleum-derived plastics spun into fibres.
Every wash cycle releases up to 700,000 microplastic fibres into waterways — and a similar order of magnitude is released straight into the air around you during a run. They've now been detected in human blood, lungs, the placenta, and breast milk.
Sweat, heat, and friction during a run pull residual industrial chemicals — antimony from PET production, PFAS “forever chemicals”, phthalate softeners — directly through the skin. These compounds are associated with endocrine disruption, inflammation, reduced fertility, and elevated cancer risk in a growing body of peer-reviewed research.
Merino is the opposite. A living fibre, grown on a sheep, that regulates temperature, wicks moisture, resists odour without antimicrobial coatings, and biodegrades fully at end of life. No plastic in. No plastic out. We weighed it against lyocell, the other natural fibre on our shortlist, before deciding — that comparison is in the research.
Every claim here is drawn from peer-reviewed studies. We've laid out the science — sources, citations, and the things we deliberately don't claim — on our research page. New here? See how merino compares to synthetic running shorts or read the FAQ.