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This guide to merino wool clothes will walk you through how to shop and what details to consider, especially if you’re seeking warmth for the outdoors!
This post is not sponsored by any of the merino wool brands listed below. We purchased and tested their products without brand collaboration.

If your hiking or camping trips have taken you through all the seasons and all sorts of weather, you know the importance of dressing for comfort.
And not just the kind of comfort that feels good when you first put something on. No — but the kind that lasts through cold, through perspiration, and through long hours.
If you’ve shopped around for the best base layers, one material that might keep popping up is merino wool.
Merino wool is often a great choice for outdoor recreation, and I’ve gathered a few tips that will make shopping for it much easier!
Here’s a guide to merino wool clothes, along with some of our favorite products tried so far. Let’s start with a few pros and cons.
Pros of Merino Wool Clothes
Merino wool is a natural fiber grown on Merino sheep. Whereas some people find traditional wool to be scratchy, merino is known for its soft texture.
It’s also great at wicking moisture from the body, which keeps you warm in the cold and cool in the heat.
It naturally resists odors and dries quickly. And it’s said to be a sustainable, eco-friendly fabric.

Some brands (like Smartwool) advertise merino wool that’s woven to include sun protection (UPF clothing.)
Cons of Merino Wool
The main drawback of merino wool is the price. It can be expensive!
Also, shopping for it can be a bit confusing, with terms like “gsm” (which we’ll explain below).
Finally, merino wool is more delicate than synthetic fabrics, so it needs to be cared for more carefully.
GSM (grams per square meter)
The GSM numbers on merino clothes are a guide to how thick the wool is.
Not every brand includes the GSM number, but when it’s listed, it can be helpful to consider.
Numbers and descriptions between brands may vary, but here’s a general guide:
150 – 180: Lightweight fabric (summer weight), may be slightly see-through.
190 – 220: Midweight, mostly opaque. Great for layering.
230 – 320: Heavyweight, fully opaque, thicker fabric.

Wool vs. Wool Blend Clothing
Much of the merino wool clothing available, especially the merino wool clothing marketed to outdoor adventurers, is not 100% wool.
Instead, it’s often a blend of merino wool and synthetic fibers (such as polyester).
Why?
Merino wool is more delicate than synthetic fabrics. Adding synthetic fabrics to the blend can provide more durability. And that’s what you want in sports clothing like leggings or bike shorts.
However, as the percentage of synthetic fabric goes higher, the less you’re getting the merino wool benefits.
It’s always a good idea to check the percentage of wool in a garment!
Sometimes the lower wool / higher synthetic blends are more affordable, but not always.
Some clothing items will even be totally synthetic on the outside with a partially wool lining, such as these Smartwool training shorts. You’ll usually see that on items that need lots of stretching ability.

Browsing for more gear for your outdoor adventures? Check out our guides to hiking and camping gear for men and women, plus our guide to women’s winter camping gear.
Our Favorite Merino Wool Clothing

I’ve been testing out various merino wool brands over the past few years. Overall I’ve been thrilled, but not every purchase was a win.
We got a small group of testers to try even more merino wool products. Here are some of the merino wool clothes we tried, listed by brand name in alphabetical order.
Branwyn
Branwyn is a new (to me) brand that sells merino wool bras and women’s undies.
What we loved:
• Their Busty bra is amazing. I wore it for all five days of our Colorado backpacking trip, and it has quickly become my favorite sports bra.

• Their merino wool undies are also wonderful! They’re slightly less “sporty” looking than other merino undies we tried, and the fabric felt mid-weight.
Icebreaker
Icebreaker is a well-established merino wool brand that makes high-quality merino wool clothes.
What we loved:
• Icebreaker wool undies for women: We tried multiple styles of their undies, and loved them all. The cuts are sporty and lightweight, and the percentage of merino wool is high (without lots of synthetics blended in). These are great for hiking and backpacking.
• Women’s half-zip pullover: This pullover is a nice midweight top that’s perfect for layering. The fabric is extremely comfortable.
• Icebreaker merino wool jogger pants for women are my favorite merino wool pant. They’re comfy and warm, and I love them as camping pajama bottoms.
What else we tried:
• Icebreaker Sphere II t-shirt: This t-shirt was lightweight and perfect for working out in hot weather, but the merino wool percentage was fairly low (about 40%), and to us, the fabric felt more like our other synthetic blend athletic-wear tops. (I accidentally tumble-dried this top instead of line-drying as the care directions said, and it shrunk. A lot.)
• Icebreaker everyday women’s cami: The fabric on this cami was itchy, and I was disappointed that the strap adjustment pieces were plastic, not metal. It made me feel like this cami wouldn’t last under heavy use.
Meriwool
What we tried:
• The Meriwool men’s boxer briefs were (impressively) 100% merino wool and were more affordable than others we tried. Our testers found these undies a little warm for day-to-day wearing, but they might be a good choice for colder days. (They didn’t have women’s undies available when we looked.)
• The Meriwool T-shirt is comfy. Despite having a lightweight description, the t-shirt we tried was a bit thicker than some other brands (which was nice in the spring and fall). The t-shirt did seem to run small. (We tried a large, and it fit more like a medium, which was a shame since the large was the largest size available.)
Smartwool
My first introduction to Smartwool was their socks. Smartwool socks are still my favorites, and I think they make great gifts for hikers too!
What we loved:
• We especially loved the classic hike full cushion socks (for hiking) and these shorter Smartwool ankle socks (for biking).
• We also tried their hike light crew socks, which come in cuter prints than the classic hiking sock and are also fabulous socks. We did prefer the more cushiony classic socks for a more comfortable hike.
• Smartwool’s base layer tee is comfy and lightweight enough to wear in the summer heat. It does definitely look like athletic wear, but has a high merino wool percentage and performed really well.
• Smartwool training shorts are also great (even though, as mentioned, only the lining is wool).
What else we tried:
• I did not care for the Smartwool sport fleece wind tights that I tried (they ran small and were too long).
WoolX
WoolX merino wool clothing comes in a variety of categories. I’ve owned a pair of their undies for years and am a fan, so I was excited to try more of their clothing options.
What we loved:
• Women’s undies: These seemed very similar to the Icebreaker undies! The fit, fabric and performance was fantastic.
• Men’s boxers: Their men’s boxers were soft, comfy and breathed well! Our testers were impressed.
• Women’s t-shirts: WoolX makes my favorite merino wool t-shirt (so far). The fabric is soft and comfy. It looks dressier than athletic wear, so it can work with both casual outfits and activewear.
• Women’s long sleeve shirts: They make both lightweight and heavier shirts, and we loved them both.
• Men’s base camp hoodie: I was initially disappointed in this hoodie because I expected it to be thicker. However, it turned out to be nice and warm (and very comfortable!).
• Merino Flex McKenna leggings: These leggings are a recycled synthetic material on the outside with wool lining, and they are WONDERFUL! We also loved the capri version. They were comfy and fit well. I do think they ran slightly big.
• Cushioned ankle sock: These were very soft and cozy. We didn’t find them as cushioned as the Smartwool socks (I still prefer Smartwool socks for athletic wear), but the WoolX socks were very comfy!
• WoolX accessories, such as their neck gator and their Kaylee beanie: The neck gator was more breathable than others I’ve tried (which I liked) and the beanie was warm, cozy and cute.
What else we tried:
• Duralite Stella leggings: These ran a little big and (sadly) the fabric pilled on the leggings within a few hours. We ordered a second pair (just in case the first were defective), but these pilled quickly too. We definitely preferred the sturdier McKenna legging.
Woolly Clothing Co.
Woolly Clothing Co. is based in Seattle and designs both activewear and casual clothes.
What we tried:
NatureDry LOFT women’s jacket: Woolly makes some pretty innovative jackets, like 100% wool all-weather winter coats. These are marketed as more natural alternatives to synthetic or chemically treated winter wear such as GoreTex or polyester.
I was excited to try this coat, and it does seem to do what they claim.
There was a lot that I liked about this coat: it’s warm, I liked the feel of the fabric, and the fit was good. However, for me, it’s unlikely to replace my other winter outerwear, because it’s slightly bulkier and heavier than I prefer.
Also, the pockets were small (too small to store a bulky glove) and didn’t zip shut (activewear coats really need zippers on the pockets!).
Women’s hipster brief undies: I’m not sure what happened here, but these ran huge. I ordered my usual size, and they were saggy and too big to wear.
Wool&
We typically focus on outdoor gear, but I’ve heard a lot about Wool& and their merino wool dresses, and wanted to include them in this post.
A friend of mine is doing the 100-day wool dress challenge and is thrilled with her dress.
We tried two of their 160 gsm (lightweight) dresses. The majority of their dresses are lightweight.
My dress (the Fiona Fit and Flare) didn’t fit quite right. It was perfect in the shoulders but too loose in the upper body. I also found myself wishing it was slightly heavier fabric and a more structured fit.

For me, this wasn’t a win.
Another friend tried the Charlotte V-Neck Midi Dress, and while she found the fit flattering, the fabric felt slightly itchy to her.
So it’s worth noting that even though most people find merino wool smooth and soft, if you have very sensitive skin it’s possible you may still pick up on a bit of irritation.
I hope this guide has acquainted you with some of the nuts and bolts of shopping for merino wool clothes. And maybe you’ve already discovered a few of your own favorite items for outdoor wear — let me know in the comments!
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