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REI Co-op Merino Midweight Bottoms - Women's Review

One of the better value merino wool options out there
REI Co-op Merino Midweight Bottoms - Women's
Credit: REI Co-op
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Price:  $80 List
Pros:  Warm, great thermoregulation, simple, great value
Cons:  Not durable, less cozy features
Manufacturer:   REI Co-op
By Amber King ⋅ Senior Review Editor  ⋅  Nov 20, 2019
Our Editors independently research, test, and rate the best products. We only make money if you purchase a product through our links, and we never accept free products from manufacturers. Learn more
  • Warmth - 30% 6.0
  • Breathability - 30% 7.0
  • Comfort and Fit - 30% 7.0
  • Durability - 10% 6.0

Our Verdict

The REI Co-op Merino Wool Midweight Bottom provides ample warmth and a vast range of thermoregulation. Composed of 200-grams of 100% Merino wool, this high-quality product balances warmth and breathability. Dump heat during your uphill struggle and keep warm while heading downhill. You'll find yourself nice and dry throughout the day while wearing this excellent base layer bottom. Not only that, but it provides the best value for a merino wool contender with a higher level of durability. Almost winning our Best Buy Award, it provides a great balance of price to performance features, while keeping you warm and cozy at a decent price.

Our Analysis and Test Results

This high-value 100% merino wool contender earns high points across most metrics for its fantastical performance in cold weather. If you seek an affordable merino wool option, this is one to consider.

Performance Comparison

REI Co-op Merino Midweight Bottoms - Women's long underwear - the rei merino wool midweight long johns offer the best value of any...
The REI Merino Wool midweight long johns offer the best value of any Merino wool contender out there. Comfortable, warm, and well fitted for only $80 retail (and lower prices online)!
Credit: Edward Kemper


Loaded with 200-grams of Merino wool, this baselayer provides sufficient warmth both while heading uphill and hunkering down for a meal. As a versatile base layer, it provides great warmth and offers a wide range of thermoregulation. The fibers are naturally hydrophobic and do a great job wicking away moisture and moving it to the outside of the fabric. When worn with a sufficient insulating layer, it can perform well in everything from deep polar temperatures to warm summer nights (on its own). This is a warm baselayer bottom with a wide range of thermoregulation.

REI Co-op Merino Midweight Bottoms - Women's long underwear - although thin, this baselayer wicks well and is composed of...
Although thin, this baselayer wicks well and is composed of 200-grams of 100% merino wool fibers. It is great for wear in cool to colds weather.
Credit: Edward Kemper


The REI Merino Wool bottoms offer a great level of breathability in addition to quick drying times and sufficient wicking power. Merino wool does a fantastic job of wicking away moisture and repelling water. In our tests where we ran up several trails in varying conditions, the fabric kept our skin dry even when sweating.

REI Co-op Merino Midweight Bottoms - Women's long underwear - running it out in the hills of colorado is always a fantastic way to...
Running it out in the hills of Colorado is always a fantastic way to test the breathability of these base layers. Here we sport the uber wicking REI Co-op merino wool base layer bottom.
Credit: Edward Kemper

In our drying tests, it proved to have a similar speed of drying as the rest. Of the merino wool contenders, it absorbed only 6.75 ounces of water, proving to be a less absorbent piece. This is in part because the fabric is lighter than other models. We also noticed that this fabric didn't readily absorb water, but repelled it until agitated underwater. This in addition to our in-field tests proves that this fabric is incredibly breathable and offers an average level of drying capabilities for a merino wool layer. Where it during high or low output activities or lounge around the campfire on cold days with a sufficient insulating layer.

Comfort & Fit

Like all bottoms constructed of Merino wool, this contender feels comfortable and plush against the skin. It has a lightweight construct (5.95 oz) that layers well underneath a pair of skinnier work pants. The elastic waistband is sewn in and doesn't offer any additional cushioning or comforts, but still feels good to wear all day. Overall, this offers a sufficient amount of comfort with a good fit.

REI Co-op Midweight Merino -- Front (model is 5'6" and 140 lbs)
REI Co-op Midweight Merino -- Front (model is 5'6" and 140 lbs)
Side profile
Side profile
REI Co-op Merino Midweight Bottoms - Women's long underwear - back
Credit: Edward Kemper

The fabrics are stretchy and provide enough room to accommodate many body types that range from thick to thin. The ankle hem is nicely elastic, stretching a broad diameter to accommodate all shapes and sizes. While the fabric is thinner than our Editor's Choice winner, it still provides decent comfort that is good enough for lounging around all day long. The fit is true to size, with the legs providing enough length for even our taller testers.

Our only caveat runs the same for most merino wool products. After running in this piece for 8 miles, we noticed that the fabric didn't retain its shape and seemed to have stretched out. While it did return to its "tighter" configuration after washing, we wish that it would maintain its form while in motion. Aside from that, we appreciate the comforts of this nicely fitting base layer bottom.

REI Co-op Merino Midweight Bottoms - Women's long underwear - the length is just right for a medium-sized person, but a larger...
The length is just right for a medium-sized person, but a larger lady might see the length being a touch short. Good thing the fabric stretches!
Credit: Edward Kemper


Being constructed of merino wool, durability is about sub-par. Through our testing period, we noted some minor pilling but no stitching fly-aways or holes. We were surprised when we went running through some sharp, bushy terrain and the fabric didn't catch, which meant that the face fabric provides some level of durability. While we didn't note any holes throughout our period, the fabrics are much more fragile than a synthetic contender. Overall, given its thinner construction of merino wool fibers, this contender provides a decent level of durability, but certainly not the best on the market.

REI Co-op Merino Midweight Bottoms - Women's long underwear - while we didn't observe any serious wear and tear, the seams aren't...
While we didn't observe any serious wear and tear, the seams aren't as flat or as well constructed as other competitors. In addition, we saw some pilling after a few washes.
Credit: Edward Kemper


This is the highest value merino wool contender tested. It costs less than other merino wool products and offers an exceptionally high level of performance. It is durable and comfortable without accumulating smells over time. If you are a person who loves merino wool and a good price, this is one we'd consider.

REI Co-op Merino Midweight Bottoms - Women's long underwear - while camping at rifle national park (a popular climbing location)...
While camping at Rifle National Park (a popular climbing location), we wear the REI Merino base layer under our hiking pants on this super frosty morning.
Credit: Edward Kemper


This high-value merino wool contender is a perfect option for pretty much any winter activity. It's perfect for any cool to cold weather activity with its ample range of thermoregulation. Wear it all day for awesome comfort and warmth.

Amber King
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