The 10 Best Women's Merino Wool Long Underwear

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This wiki has been updated 22 times since it was first published in February of 2017. Merino wool is prized because it comes from sheep who survive in the New Zealand Alps, making it remarkably warm. In addition to helping regulate body temperature, this natural fiber is sustainably sourced and has antimicrobial properties. Women’s long underwear made from this material are flattering and comfortable, so you’ll love layering them beneath outwear or simply lounging at home in them. When users buy our independently chosen editorial choices, we may earn commissions to help fund the Wiki.

1. Minus33 803 Franconia

2. Ridge Aspect Midweight

3. Icebreaker 260 Zone Leggings

Editor's Notes

September 28, 2020:

Coming on board today is the Ridge Aspect Midweight which, unlike many other long-sleeve undershirts, features jersey-style raglan sleeves. These resemble the sleeves of a baseball jersey and are designed to foster unrestricted arm movement, which you’ll appreciate when doing many cold-weather sports and activities. It’s available in several solid colors, as well as a couple of contrasting two-tone designs. It serves as a mid-weight base layer and is made to dry quickly. Thumb loops help keep the sleeves in place, so your arms will stay warm and you’ll be able to pull a jacket over the shirt with ease. Its long cut helps it stay tucked into your pants, and a printed neck label eliminates the annoyance and itchiness of a tab.

In this update, we also added in a couple of pairs of bottoms including the Icebreaker 260 Zone Leggings, which receive high marks all around. They’re thoughtfully designed with fabric panels in two different weights. The thick ones keep you warm, while the strategically placed lighter mesh sections ensure proper ventilation. The newly added Le Bent Le Base Layer are made to keep you dry by moving sweat away from the skin, and their soft fibers are designed to keep them itch-free and comfortable. When you’re not using them underneath jeans or ski pants in cold weather, you might find yourself lounging around the house in them. They feature 4-way stretchy fabric and provide some protection from the sun’s harmful rays. In adding these new pieces, we removed the Icebreaker Butter Rib, which doesn’t provide as much coverage as most others and is only suitable for moderate climates. We also removed the Ridge Inversion Mids, which various users say are not flexible enough, as well as the currently-unavailable WoolX X753 Heavyweight.

October 15, 2018:

We expanded the list substantially to ensure there are light, mid, and heavyweight options in tops and bottoms. We also focused on more form-fitting choices.

Special Honors

L.L.Bean Women’s Cresta Wool Ultralight 150 This long-sleeve base layer is made with itch-free 100% merino wool with fibers that trap heat and provide much warmth for the weight. The flatlock seams ensure a comfortable fit, while the thumb cuffs help keep your hands and wrists warm. It’s naturally resistant to odors, with a light weight and a fine-gauge knit construction. To care for it, simply place it in the washing machine and allow it to line dry.

4. WoolX Alpine Heavyweight

This item has been flagged for editorial review and is not available.

5. Minus33 801 Magalloway

6. Meriwool Midweight

7. Le Bent Le Base Layer

8. SmartWool NTS Mid 250

9. EcoAble Apparel Thermal

10. Woolx Avery Midweight

This item has been flagged for editorial review and is not available.

Karen Bennett
Last updated by Karen Bennett

Karen Bennett lives in Chicago with her family, and when she’s not writing, she can usually be found practicing yoga or cheering on her kids at soccer games. She holds a master’s degree in journalism and a bachelor’s in English, and her writing has been published in various local newspapers, as well as “The Cheat Sheet,” “Illinois Legal Times,” and “USA Today.” She has also written search engine news page headlines and worked as a product manager for a digital marketing company. Her expertise is in literature, nonfiction, textbooks, home products, kids' games and toys, hardware, teaching accessories, and art materials.

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