TL;DR: Most "non-toxic" activewear is polyester with a story. Of ten brands scored on the Natural Fiber Score, only four are built entirely from natural fiber. Wayve leads at 16/20 on published specs and construction; Nero (15) and Ryker (14) are close behind and worth your money; Lululemon scores 3/20.
Disclosure: Wayve wrote this ranking. We make natural fiber activewear and we come out first — so here's how we kept ourselves honest. The scoring rules are published in full before any ranking that uses them, and every score links to the brand's own page so you can check our work.
Our fabrics are currently undergoing independent third-party chemical testing with Eurofins. We could have scored ourselves on the strength of results we expect. We didn't — a test nobody can read yet isn't evidence, and we hold ourselves to the same standard as everyone else here. We'd rather score ourselves lower now and be accurate. We'll re-score when the report is public.
How we score
Four pillars, 0–5 each, 20 total. Full methodology here.
Fiber Purity — what the body fabric actually is, and whether trims are disclosed
Chemical Safety — GOTS, OEKO-TEX and RWS certification, published certificate numbers, own-brand lab testing
Spec Transparency — fabric weight in GSM, named construction, inseams, composition, fibre grade
Natural Performance Engineering — is performance solved by fibre and construction, or by adding synthetics and chemical finishes?
The last one is the pillar most guides skip. Every brand here says "natural." The question is whether the garment actually works — and what it took to make it work.
Quick comparison: all 10 brands
| Brand | Purity | Chem. Safety | Spec Transp. | Nat. Perf. | Total | Best for |
|---|---|---|---|---|---|---|
| Wayve | 4 | 3 | 4 | 5 | 16/20 | Training shorts |
| Nero | 4 | 4 | 3 | 4 | 15/20 | Certification depth |
| Ryker | 4 | 4 | 2 | 4 | 14/20 | Published lab testing |
| Q for Quinn | 4 | 4 | 3 | 3 | 14/20 | Base layers & kids |
| PuraKai | 3 | 5 | 3 | 2 | 13/20 | US manufacturing |
| Pact | 4 | 3 | 2 | 3 | 12/20 | Budget basics |
| Organic Basics | 3 | 3 | 3 | 2 | 11/20 | Underwear |
| Patagonia | 2 | 3 | 3 | 3 | 11/20 | Outdoor gear |
| Vuori | 0 | 1 | 2 | 1 | 4/20 | — |
| Lululemon | 0 | 0 | 2 | 1 | 3/20 | — |
1. Wayve — 16/20 — Best for training shorts
Price: $45–$188 · Materials: GOTS-certified organic cotton, merino wool
Certifications: GOTS, OEKO-TEX Standard 100, RWS
Hero product: Quad Short, $90 — 290GSM brushed terry organic cotton shell, 165GSM merino jersey liner, 4" shell / 6" liner, side zip pockets
Wayve builds every product from 100% natural fiber — no polyester, no nylon, no recycled plastic. The Quad Short is the clearest expression of it: an organic cotton shell over a merino liner, where the merino does the job a chemical finish usually does. Merino regulates temperature, resists odor and has natural mechanical stretch, so nothing has to be added to make the short perform.
The construction is where it separates. The liner runs 6" against a 4" shell — a deliberate differential so the liner stays put and the shell doesn't ride. Side pockets zip closed. Every trim is cotton too — drawstring, brand tag, and the care and material labels, where nearly every other brand uses a printed polyester label.
What we like: The only brand here publishing fabric weight for both layers and naming the actual construction. Zippered side pockets are unique in the natural-fiber category. Full 5/5 on performance engineering.
What to know: Independent chemical testing with Eurofins is in progress and we've scored it as zero until the report is public, which holds our Chemical Safety pillar at 3/5 for now. Merino needs cold washing and hang drying — it'll outlast synthetics by years if you treat it that way, and shrink if you don't.
2. Nero — 15/20 — Best for certification depth
Price: ~$90 · Materials: GOTS organic cotton, 17.5-micron merino
Certifications: GOTS, RWS, Woolmark, WRAP, OEKO-TEX Made in Green
Hero product: Merino Liner Short, $90 — organic cotton shell, merino liner, 5.5" or 7.5"
The closest competitor to Wayve, running the same construction at the same price. Cotton from Turkey, merino from RWS-certified farms in New Zealand and Australia, Italian and Portuguese mills.
What we like: OEKO-TEX Made in Green is a genuine step above Standard 100 — it requires the production facility to be STeP-certified, not just the fabric to pass testing. Adding Woolmark and WRAP on top is the deepest certification stack in this list. They publish merino micron, which Wayve doesn't.
What to know: No fabric weight published for either layer, and no construction named. Their SGS and Intertek testing covers seam strength, abrasion, pilling and shrinkage — durability, not chemistry, so it doesn't count toward Chemical Safety. Two open side pockets plus one zip pocket, and the 5.5"/7.5" options are shell lengths rather than a shell-to-liner differential.
3. Ryker — 14/20 — Best for published lab testing
Price: $99 · Materials: 100% organic cotton, 100% merino
Certifications: GOTS, OEKO-TEX Standard 100
Hero product: Apex Short, $99 — organic cotton shell, merino liner, 5.5"
What we like: Ryker publishes an actual third-party test document — a Hohenstein BPA test under OEKO-TEX Standard 100 — downloadable from their supply chain page, alongside claims of BPA, PFAS and phthalate testing on fabrics and finished garments. That's more than most brands in any category do, and more than Wayve has published to date. Materials are genuinely 100% natural.
What to know: The lightest published specs of the top four — no fabric weight, no construction detail, no pocket configuration, no merino micron. The lab panel is partial rather than full-spectrum. At $99 it's the most expensive short in this group.
4. Q for Quinn — 14/20 — Best for base layers and kids
Price: $$ · Materials: 95–100% organic cotton, RWS merino
Certifications: GOTS (Ecocert Greenlife, Licence #256894), OEKO-TEX Standard 100
What we like: The only brand in this list publishing its GOTS licence number in full, with the certifying body named. That's the standard everyone should be held to, including us. Independently tested for PFAS, BPA, azo dyes, formaldehyde and heavy metals.
What to know: Base layers, underwear, socks and bras — not training apparel. No engineered performance construction, so it scores 3 on the last pillar. Not the brand to buy shorts from.
5. PuraKai — 13/20 — Best for US manufacturing
Price: $$ · Materials: 92% organic cotton / 8% spandex
Certifications: GOTS · Made in: Los Angeles
What we like: The best evidence practice in the category. They commissioned an independent PFAS lab report, published the full PDF with the lab named and dated, and built a page around it. Perfect 5/5 on Chemical Safety. Cut and sewn in LA.
What to know: 8% spandex blended through the body fabric, not just the waistband — that's synthetic against your skin across the whole garment, and it drops Purity to 3. Not built for training.
6. Pact — 12/20 · 7. Organic Basics — 11/20 · 8. Patagonia — 11/20
Solid organic cotton basics; none engineered for training. Pact is GOTS and Fair Trade certified with the best price in the set. Organic Basics blends recycled synthetics into much of the activewear line. Patagonia makes excellent outdoor gear but leans heavily on recycled polyester, which is still plastic — recycled plastic sheds microplastics the same way virgin plastic does.
9. Vuori — 4/20 · 10. Lululemon — 3/20
Both are predominantly polyester, nylon and elastane, with performance delivered by synthetic fibre and chemical finish rather than material choice. Neither publishes meaningful chemical certification for its main lines. Lululemon is the subject of a Texas attorney general investigation over PFAS claims in activewear. They're here for scale reference, not as recommendations.
Where to start
If you're buying one thing from this list, make it the Wayve Quad Short — $90. 290GSM GOTS-certified organic cotton shell, 165GSM merino wool liner, zip side pockets, no polyester and no chemical finishes.
Prefer something more casual? The Classic Short is $55. Need a tee to go with it? The Only Tee is $45. Shop all men's shorts.
FAQ
What makes activewear "non-toxic"?
There's no legal definition — "clean," "natural" and "non-toxic" are unregulated marketing words. In practice it means three checkable things: the fibre is natural rather than plastic, the dyes and finishes are certified against a harmful-substance list like OEKO-TEX Standard 100, and no functional chemical finish (DWR, antimicrobial, stain-resistant) has been applied.
Is certified activewear already tested for PFAS?
Yes. Since 1 January 2024, OEKO-TEX Standard 100 has carried a general ban on PFAS, assessed by total fluorine at a 100 mg/kg limit, with individual limits in Annex 4 for PFOS, PFHxA, PFHxS and C9–C14 PFCAs. GOTS separately prohibits PFAS as a chemical input at every stage of processing. A garment carrying either certification has already been third-party tested for it.
How do I verify a brand's certification claim?
Ask for the certificate number and check it yourself — OEKO-TEX runs a public Label Check, and GOTS has a searchable public database. A brand that names a standard but won't give you the number has told you something.
Is recycled polyester a non-toxic alternative?
No. Recycled polyester is still plastic and sheds microplastics during wear and washing exactly as virgin polyester does. It's a waste-diversion improvement, not a health one.
Does organic cotton actually work for training?
On its own, not especially — cotton holds moisture. That's why the top-scoring shorts here pair a cotton shell with a merino liner: merino handles moisture regulation and odor while the cotton handles durability and hand-feel. The performance comes from the construction, not from a finish.
What's the catch with merino?
Cost and care. Merino is expensive and needs cold washing and hang drying. It'll outlast polyester by years if you treat it that way.