| Inseam | Waist |
| 5" - 7" | 28-30" (S) |
|
5" - 7" |
30-32" (M) |
|
5" - 7" |
34-36" (L) |
|
5" - 7" |
38-40" (XL) |
| 5" - 7" | 42-46" (XXL) |
★★★★★
Over 50,000+ Shorts Sold
7 Reasons To Ditch Toxic Polyester
25%
Men's testosterone has dropped 25% in the last 20 years
92%
Of gym shorts are made from polyester plastic
0
Brands talking about what that's doing to your body
REASON #01
The Infertility & Hormone Trap
Wearing polyester apparel was shown to cause electrostatic stress that directly suppressed sperm production, degraded motility, and measurably decreased testicular size. Your body is designed to breathe, not to be suffocated in synthetic, heat-trapping petrochemical fabrics.
The Clinical Proof:
European Urology and the Archives of Andrology
- The Result: The group wearing pure synthetic fabric suffered rapid drops in sperm count, reduced testosterone markers, and measurable testicular atrophy within 140 days. Natural fibers had zero effect.
REASON #02
2. "Recycled Polyester" Greenwashing Scam
You were told buying shorts made of recycled water bottles was saving the planet. Here’s what they didn’t tell you:
- Recent laboratory research shows that recycled polyester sheds about 55% more microplastic particles than virgin polyester.
REASON #03
Tiny plastic particles from polyester are being found inside men's testicles.
Scrotal skin is paper-thin and absorbs compounds up to 40x faster than the rest of your body.
Study (Toxicological Sciences, University of New Mexico): Tested human testicular tissue and detected microplastics in 100% of samples, the higher the plastic saturation inside the tissue, the steeper the drop in sperm count.
REASON #04
Gym brands know. They just make more money saying nothing.
Polyester costs about $2 per meter to make. Merino wool can cost up to $50 per meter. That's why 92% of gym wear is polyester. Not because it's better for you. Because it's better for their margins. The silence isn't an accident, it's a business decision. You're cheaper to keep uninformed.
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
Ships in 1-2 weeks
99-Day Extended Returns & Exchanges
BUY ONE GET ONE 25% OFFFree Shipping On 2+ Items
SPRING SALE
"The material is next-level — breathable, soft, and somehow manages to feel both lightweight and durable at the same time"
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REASON #05
Working out is actually the worst time to be wearing plastic against your skin.
When you exercise, your pores open up to let sweat out. That's also when they're most open to letting things in. Sweat acts like a solvent that pulls chemicals off the fabric, and your open pores absorb them straight into your bloodstream.
REASON #06
Polyester traps heat exactly where your body needs to stay cool.
For your body to produce testosterone and healthy sperm properly, your testicles need to stay a couple of degrees cooler than the rest of you. That's literally why they hang outside the body. Polyester traps heat and holds moisture against the skin, the worst possible combination for that area of your body.
A study of 656 men found that those who wore breathable, natural fabrics had 25% higher sperm count than men who wore tight synthetic alternatives.
REASON #07
Men's testosterone has been crashing for decades and scientists think plastic chemicals are a big reason why.
A 2021 study of over 4,000 men confirmed that young men today have nearly 25% less testosterone than young men did 20 years ago. Doctors and researchers keep pointing to plastic chemicals in the environment as one of the main things they can't otherwise explain.
SO WHAT DO YOU WEAR INSTEAD?
Nero shorts are made with a New Zealand merino wool Liner and organic cotton shell. No polyester. No plastic chemicals. No microplastics shedding against your skin.
Here's what that actually means:
No plastic chemicals against your body
No phthalates, no BPA, nothing that interferes with your hormones.
Sweat moves away from your skin
Merino pulls moisture away from the body. Polyester pushes it back toward you.
No microplastics
Natural fibres don't shed plastic particles. Full stop.
Your body stays at the right temperature
Merino wool naturally regulates heat, keeping things cooler where they need to be cool.
Sourced responsibly
New Zealand RWS-certified merino. Certified organic cotton. Nothing hidden in the supply chain.
99-DAY MONEY-BACK GUARANTEE
Wear them for 99 days. If you don't love them, or if you don't feel the difference, return them for a full refund. No forms. No questions. No hassle.
We're that confident.
YOU TRAIN HARD. WHAT YOU WEAR SHOULD WORK WITH YOU, NOT AGAINST YOU.
Every session in polyester is a session where the very thing you're trying to build, testosterone, strength, performance, is being quietly undermined by what's pressed against your body.
You deserve better than a Coke bottle with a waistband.
SHOP NERO MERINO SHORTS
★★★★★ 4.8/5 (550+ Reviews)
Over 30,000+ Shorts Sold
Nero prices increase every Monday as wool costs rise. Today's price won't be here next week.
