10 Best Base Layer Women 2026 in the United States

The Cuddl Duds Thermal Underwear for Women offers a warm and comfortable base layer ideal for cold weather thanks to its brushed fleece lining inside and soft matte finish outside. The set includes a long-sleeve top with thumbholes and leggings with a modern rise, providing good coverage and comfort without feeling bulky. Made from a polyester and spandex blend, it offers stretchy movement, which helps when layering or wearing it alone.

Its fabric is moisture-wicking, meaning it helps pull sweat away from your skin to keep you dry, and it also features protection against UV rays, which is a nice bonus for outdoor use. The lightweight design (around 15 ounces) makes it convenient to wear under other clothing or on its own for lounging. The seams appear designed for comfort, and the tag-free label helps avoid irritation.

This set is a solid choice for women looking for a cozy, flexible base layer for winter activities or casual wear, but if you need heavy-duty odor control or natural fibers like merino wool, you might want to explore other options.

The SmartWool Women's Classic Thermal Merino Base Layer Bottom is designed for cold-weather outdoor activities like skiing, running, and hiking. Made from 100% Merino wool, it offers excellent warmth and natural moisture-wicking to keep you dry and comfortable. The fabric is midweight, providing a good balance of insulation without feeling too heavy. These bottoms have a slim fit that moves well with your body while showing a flattering silhouette. Flatlock seams reduce chafing, which is great for long wear, and the fabric’s breathability helps regulate temperature during active use. Merino wool also naturally controls odor, so you can wear these for extended periods without worrying about smell.

On the downside, since it’s pure wool, it requires gentle washing and careful drying to maintain its shape and softness. Also, the slim fit may not suit everyone’s preferences if you want a looser base layer. Weighing just over 7 ounces, it’s light enough for layering but may feel warmer than thinner options if you prefer less insulation.

This base layer bottom is a reliable choice for women wanting a warm, breathable, and comfortable layer that works well in cold conditions with good moisture and odor control.

The Merino.tech Merino Wool Base Layer Set for women offers a reliable midweight option at 250 g/m², which is great for cooler weather activities like hiking or layering in winter. Made from 100% superfine 17.5 micron merino wool, it promises softness and comfort without the itchiness often associated with wool. This makes it suitable for wearing all day without discomfort.

It naturally wicks moisture away from the skin and resists odors, helping you stay dry and fresh during physical activity. The breathable fabric also helps regulate body temperature, so you won’t overheat or get too cold. The package includes a top, leggings, and a bonus pair of merino hiking socks, which adds value. Care instructions recommend hand washing or using a delicate cycle and flat drying, which might require more effort compared to synthetic base layers.

This base layer set is a solid, natural-fiber choice for women looking for comfort, odor control, and moisture management in a midweight layer, especially those who appreciate the softness of superfine merino wool and don’t mind the gentle care it requires.