★★★★★

4.8/5 · 30,000+ sold

Why the wealthiest men in the world wear these shorts.

Six reasons the most successful men have made the switch.

Shop the Active Short See the 6 reasons

92%

Of activewear is polyester plastic

Microplastics absorbed every week

Synthetic fibres in a Nero short

92%

Of activewear is polyester plastic

Microplastics absorbed every week

Synthetic fibres in a Nero short

Reason 01 — On Standards

The world's wealthiest men don't wear recycled plastic.

The ultra-wealthy share one habit: they stop tolerating "good enough." Every choice — from the car to the tailor to the gym short — reflects a commitment to quality that compounds over a lifetime.

92% of all activewear is made from polyester — a petroleum byproduct chosen because it costs a fraction of natural fibre. Mass-market brands profit. Their customers sweat in plastic.

Source: Global Textile Market Report

Reason 02 — Temperature & Performance

Merino wool thermoregulates better than any synthetic on earth.

Every high-performance sports brand claims to keep you cool. Most achieve it with petroleum-derived synthetics and a large marketing budget. Merino wool does it through millions of years of biological engineering.

Research published in the Journal of Thermal Biology confirmed merino wool maintained significantly lower skin temperatures during sustained exercise compared to synthetic alternatives.

Source: Journal of Thermal Biology

Reason 03 — The Science

Polyester is poisoning you during every workout.

This isn't hyperbole. This is peer-reviewed science. When you exercise in polyester shorts, sweat opens your pores and your skin absorbs what's against it — including the microplastics and chemical additives woven into every synthetic fibre.

A landmark clinical study found polyester exposure caused a measurable decline in testosterone, reduced sperm production, and shrank testicular size in male subjects — with no other lifestyle change.

The average person absorbs 5 grams of microplastics per week. The weight of a credit card.

Sources: NCBI / PubMed, NIH, Environmental Health Perspectives

Reason 04 — Provenance

Sourced like a Loro Piana suit. Built for the gym.

The shell is certified organic cotton from the agricultural heartlands of Turkey — one of the world's oldest textile regions. The liner is 100% New Zealand merino wool, RWS certified, from farms where animal welfare and fibre quality are the same priority.

This is the same sourcing standard Loro Piana applies to their £3,000 trousers. Nero applies it to your active short.

RWS Certified

Responsible wool

GOTS Organic

100% pure cotton

OEKO-TEX®

Chemical tested

1 / 5

★★★★★

4.8/5 · 400+ reviews

Active Merino Liner Short

All-natural athletic shorts designed for movement and built for durability.

Regulates Temperature

All Natural Fabrics

Moisture-Wicking

Soft As Cashmere

New Zealand Merino

Colour: Black

Size: M

Inseam: 5"

99-Day Returns & Exchanges

Spring Sale: Buy One Get One 25% Off

Auto-applied at checkout · Free shipping on 2+

★★★★★

"The material is next-level — breathable, soft, and somehow manages to feel both lightweight and durable at the same time."

JOEL J. Verified Buyer

Reason 05 — Performance

It outperforms every synthetic short in the properties that actually matter.

Fast-fashion gym brands compete on stretch and colourways. The metrics that matter to a man who takes his health seriously are different: odour resistance across multiple wears, moisture management without trapping heat, and zero contribution to systemic inflammation.

Merino wool is naturally anti-microbial. Nero shorts stay fresh through multiple sessions where synthetic shorts need washing after every single use.

Side by Side

Nero vs. Polyester

The difference isn't marketing. It's measurable.

100% natural fibres

RWS Certified GOTS 100% Organic OEKO-TEX®

Natural odour resistance
Active thermoregulation
Zero microplastic shedding
Fully biodegradable
Confirmed hormone safe
Cashmere-like skin feel

Polyester

Synthetic · Petroleum

Uncertified Chemically Treated Plastic-Based

Needs chemical treatment
Passive thermoregulation only
700k+ microplastics per wash
200+ years to break down
Hormone safety disputed
Varies — often plastic-feel

Shop the Active Short →

Reason 06 — The Guarantee

Try them for 99 days. If they're not the best shorts you've ever worn, we'll refund every penny.

The confidence we have in this product doesn't come from marketing. It comes from 400+ five-star reviews, repeat customers, and the conviction that once you've trained in 100% natural fabric, going back to polyester is a conscious decision to train in plastic.

We are that confident.

Shop with 99-Day Guarantee →

Day money-back

Full refund, no questions.

400+

5-star reviews

Average rating 4.8/5.

Questions asked

Returns handled in 1 click.

The Fabric

Built from two of nature's finest fibres.

Every material choice was made with one question: is this the best possible option, or are we compromising?

100%
Natural

Zero plastic.
Zero compromise.

From certified New Zealand merino farms to GOTS-approved Turkish cotton — every fibre is traceable.

Shell

100% Organic Cotton

GOTS-certified, sourced from Turkey. Breathable, durable, chemical-free.

Liner

100% Merino Wool

New Zealand RWS-certified. Ultra-fine 17.5 micron, thermoregulating, naturally anti-microbial.

Certification

RWS + GOTS + OEKO-TEX®

Full supply chain traceability. From farm to fabric to you.

Synthetics

Zero. None. Ever.

No polyester. No microplastic shedding. No endocrine disruptors. Nothing.

500+ Verified Reviews

What high-performers
are saying.

★★★★★ 4.8 /5

★★★★★

Verified

"I've worn Lululemon, Vuori. Nothing comes close to how these feel against the skin. It's a completely different category."

James R.

Private Equity · New York

★★★★★

Verified

"The temperature regulation is genuinely remarkable. I've worn these through hot yoga, morning runs, and long-haul flights. They just work."

David H.

Founder & CEO · London

★★★★★

Verified

"I didn't think I'd care this much about what I train in. Then I read about microplastics and testosterone. Now I won't go back. Period."

Mark S.

Investor · Zurich

★★★★★

Verified

"Bought two pairs. The merino liner — no chafing, no smell after three sessions. My polyester shorts are in the bin."

Tom L.

Software Engineer · Dublin

★★★★★

Verified

"Wore them on a 12-hour flight. Still felt fresh when I landed. Can't go back."

Alex K.

Consultant · Singapore

★★★★★

Verified

"Best shorts I've ever owned. Lift, run, hot yoga — they handle it all. Plastic-free is just a bonus."

Ryan B.

Personal Trainer · Melbourne

Shop the Active Short →

The Choice Is Simple

Train in the best.
Or keep sweating
in plastic.

Nero Active Shorts. 100% organic cotton shell. 100% merino wool liner. Zero synthetics. Zero compromise. Worn by the world's most successful men.

You deserve better than a Coke bottle with a waistband.

Shop the Active Short →

★★★★★ 4.8/5 (500+ Reviews)

Over 30,000+ Shorts Sold

Nero prices increase every Monday as wool costs rise. Today's price won't be here next week.

Why the wealthiest men in the world wear these shorts.

The world's wealthiest men don't wear recycled plastic.

Merino wool thermoregulates better than any synthetic on earth.

Polyester is poisoning you during every workout.

Sourced like a Loro Piana suit. Built for the gym.

Active Merino Liner Short

It outperforms every synthetic short in the properties that actually matter.

Nero vs. Polyester

Try them for 99 days. If they're not the best shorts you've ever worn, we'll refund every penny.

Built from two of nature's finest fibres.

Zero plastic.Zero compromise.

What high-performers are saying.

Train in the best.Or keep sweatingin plastic.

Zero plastic.
Zero compromise.

What high-performers
are saying.

Train in the best.
Or keep sweating
in plastic.