10 Best Long Underwear For Women 2026 in the United States

The Merino.tech Merino Wool Base Layer Women Set consists of a top and bottom made from 100% superfine 17.5-micron merino wool, plus a beanie. This set is midweight, with a fabric weight of 250 g/m², providing good warmth without being too heavy. The natural properties of merino wool make this set highly effective in moisture-wicking and odor resistance, keeping you dry and fresh throughout the day.

The material is also breathable, helping to regulate your body temperature, which is beneficial for year-round use. The fit is designed to be comfortable for daily wear, with the fabric being soft and non-itchy. However, the set requires special care; it should be washed on a delicate cycle and laid flat to dry, which may be inconvenient for some users.

Additionally, imported origin could imply a higher price point. This base layer is ideal for women seeking comfortable, versatile, and high-performance long underwear, especially those who spend a lot of time outdoors or engage in active pursuits. The inclusion of a Merino Wool Beanie adds extra value to the purchase.

The Cuddl Duds Women's Thermal Underwear set is designed to keep you warm and comfortable in cold weather with its heavyweight fabric that features a brushed fleece inside for softness and warmth. Made mostly of polyester with some spandex, it offers a good stretch, making it easy to move around whether you're active or relaxing. The moisture-wicking material helps pull sweat away from your skin, keeping you dry and more comfortable during physical activities or daily wear. It also provides added protection from the sun with a 50+ UV rating, which is a nice bonus if you spend time outdoors.

The fit is thoughtfully designed, with modern rise leggings and thumbholes in the sleeves to keep the top in place and add extra coverage. The seams are likely designed to reduce irritation, and the tag-free labels contribute to enhanced comfort. Since the fabric is dense and heavyweight, it might feel a bit bulky for some, especially if you prefer very lightweight base layers.

This set is an excellent choice for women looking for cozy, reliable thermal underwear that can serve both as a base layer or be worn alone at home or outdoors in cooler weather.

The Merino.tech Merino Wool Base Layer Women Set is a great choice if you're looking for comfortable, warm long underwear crafted from 100% superfine merino wool. This midweight set (250 g/m²) strikes a nice balance between warmth and breathability, making it suitable for cooler weather activities like hiking or layering in winter. The fabric is soft and fine enough to avoid itchiness, which can be a problem with some wool products. It’s designed to fit well without bunching or rubbing, though sizing and fit can vary slightly by body shape.

One standout feature is its natural moisture-wicking and odor-resistant properties, helping you stay dry and fresh during extended wear. The construction appears thoughtful, but hand washing and flat drying are recommended to maintain softness and shape, which may require a bit more care than synthetic alternatives. The package even includes merino wool hiking socks, adding good value.

If you want a natural, breathable base layer that manages moisture effectively and resists odors, this set is a solid option. For those who prefer machine-washable or lighter-weight base layers for high-intensity activities, exploring other choices might be beneficial.