★★★★★ 5/5  ·  100% Merino Wool Activewear

Your gym shirt is made of plastic. This one isn't.

Five reasons athletes who care about what touches their skin are making the switch to merino wool.

35%
Of ocean microplastic pollution comes from textiles
700K
Microplastic fibers shed per load of synthetics
0
Synthetic fabrics in any Aiua garment
Customer wearing Aiua merino wool tank top
★★★★★

"So comfy. It was perfect for my Pilates class. And no smell :)"

Eli L.
Merino wool tank top
✓ Verified purchase
01

Polyester Is Made Of Plastic

Polyester is petroleum-based plastic. It dominates activewear because it can take a beating and is cheap to produce at scale, But ultimately, wearing the typical performance tee is like wrapping yourself in cellophane.

Every time you sweat in polyester, your pores open and can absorb microplastics shed from the fabric. We've accepted it as the default and the $200B activewear industry has no incentive to talk about it.

Aiua's approach: What goes on your skin deserves as much care as what goes in your body. Every garment we make is 100% merino wool. No polyester, no nylon, no spandex. Zero synthetic fabrics of any kind.
Plastic bottles for polyester
02

Merino Regulates Temperature. Polyester Just Traps Heat.

Polyester wicks moisture by spreading sweat across the fabric surface, resulting in a clammy, sticky feeling that clings to skin.

Merino wool fibers actively respond to humidity and temperature changes. They absorb moisture vapor before you even feel wet, and release heat when conditions shift, resulting in all-day comfort. The best part is this is an inherent property of the fiber itself, not some chemical treatment.

What this means in practice: You stay cooler in summer, warmer in winter, and dry year-round.
man in nature wearing Aiua clothes

Feel the Difference Natural Makes

100% merino wool. No synthetic fabrics. Free shipping over $100 plus 15% off with code "hellowool".

Aiua Men's Merino Tank Top
Men's Merino Tank Top
100% Merino Wool
$65
Size
Color
Add to Cart — $65
Free shipping on orders over $100 · 30-day returns
Aiua Men's Merino T-Shirt in Rainier
Men's Merino T-Shirt
100% Merino Wool
$85
Size
Color
Add to Cart — $85
Free shipping on orders over $100 · 30-day returns
Aiua Men's Merino Quarter-Zip
Men's Merino Quarter-Zip
100% Merino Wool
$130
Size
Color
Add to Cart — $130
Free shipping on orders over $100 · 30-day returns
Aiua Women's Merino Tank Top in Salmonberry Dust
Women's Merino Tank Top
100% Merino Wool
$65
Size
Color
Add to Cart — $65
Free shipping on orders over $100 · 30-day returns
Aiua Women's Merino T-Shirt in Cloud
Women's Merino T-Shirt
100% Merino Wool
$85
Size
Color
Add to Cart — $85
Free shipping on orders over $100 · 30-day returns
Aiua Women's Merino Quarter-Zip
Women's Merino Quarter-Zip
100% Merino Wool
$130
Size
Color
Add to Cart — $130
Free shipping on orders over $100 · 30-day returns
03

Polyester is a Breeding Ground for Odors. And Bacteria.

Gym clothes smell. It's just what they do. But it's not your fault – it's bacteria thriving on polyester. Synthetic fibers create the perfect environment for odor-causing bacteria – another thing we've all accepted as the default.

Merino wool's natural lanolin and fiber structure resist bacterial growth at a microscopic level, naturally. Wear an Aiua shirt for two, three, four days — then try that with your polyester.

close-up of polyester
04

Merino Feels Luxuriously Soft

When most people hear "wool," they think of a scratchy holiday sweater. Merino is different. At 18.5 microns, our fibers are three times finer than a human hair, making for a luxuriously soft feel.

The result is a fabric that feels like a high-end cotton tee, with the inherent performance of merino fibers: temperature-regulating, odor-resistant, moisture-managing, and completely natural. Great for sensitive skin.

close-up of merino fabrics
05

Merino Biodegrades. Polyester Pollutes.

A polyester shirt takes 200+ years to decompose in a landfill. Every wash of synthetic clothes sends hundreds of thousands of plastic microfibers into waterways.

Merino wool is a renewable fiber that biodegrades naturally. When an Aiua garment reaches end of life, it can return to the earth. Future generations will thank you.

We're certified: Every Aiua garment carries OEKO-TEX, RWS, and BSCI certifications.
wool biodegrading
Performance, without the plastic fabric.
Shop the Collection

How Aiua Stacks Up

Typical Activewear Aiua
MaterialPolyester (plastic)100% Merino Wool
Odor ControlChemical treatmentsNaturally antimicrobial
Microplastics700K fibers/washZero
ThermoregulationTraps heatActive temp regulation
CertificationsUsually noneOEKO-TEX · RWS · BSCI
End of Life200+ years in landfillFully biodegradable in 12-18 months
WearabilityWash after every useMultiple days between washes

What Customers are Saying

From verified Aiua customers

Customer in Aiua merino wool
★★★★★

"I've probably purchased merino shirts from 15 different companies trying to find the right fit, and these are easily some of my favorites. Perfect lightweight summer merino shirt. At 6'2" and 175 lbs, finding merino shirts that are actually long enough is somehow harder than assembling IKEA furniture without leftover screws. These fit just right. Not skin tight, not baggy, just super comfortable."

— Just a Guy
Quarter-Zip
Customer in Aiua merino wool
★★★★★

"So comfy. It was perfect for my Pilates class. And no smell :)"

— Eli L.
Tank Top
Customer in Aiua merino wool
★★★★★

"The tshirt is so comfortable and soft - it's a clear upgrade from my normal gymwear!"

— William W.
T-Shirt
Customer in Aiua merino wool
★★★★★

"I love this shirt! It's super comfortable and breathable both for working out and just wearing wherever. And I like the kinda cropped fit that goes perfectly with high waisted leggings and pants."

— Sanne S.
T-Shirt
Aiua Clothing

Performance Without the Plastic Fabric.

Free shipping over $100  ·  30-day hassle-free returns

Shop Now
OEKO-TEX · RWS · BSCI Certified
100% Merino Wool  ·  Free Shipping over $100 Shop Now