10 Best Long Underwear For Women 2026 in the United States

The Cuddl Duds Thermal Underwear set for women is designed to keep you warm and comfortable during cold weather with its brushed fleece lining and soft outer fabric. Made mostly of polyester with a bit of spandex, this set offers a good stretch that makes it easy to move around without feeling restricted. It’s lightweight at just under 15 ounces, which means it won’t feel bulky when worn as a base layer or even on its own for lounging.

The fit is modern and practical, featuring a thumbhole on the sleeves and a comfortable rise on the leggings, which helps with staying warm and adds convenience. The seams and construction appear smooth and tag-free, reducing chances of irritation during long wear. The fabric is designed to wick moisture away, so you stay dry even if you sweat a little, and it offers breathability to prevent overheating.

Additionally, the material blocks 50+ UV rays, which is a nice bonus if you spend time outdoors in winter. The fabric is mostly synthetic, which might not feel as natural as cotton to some users, and while it helps with moisture, it may not be as breathable as lightweight wool options. For softness, warmth, and ease of movement, the Cuddl Duds thermal set is a solid choice for women looking for a reliable, cozy base layer for cold weather or casual indoor wear.

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 Grenasasilk Women's Silk Long Underwear is crafted from 100% natural mulberry silk, known for its softness, lightweight, and breathability, making it suitable for cold weather. The material is hypoallergenic and gentle on sensitive or allergy-prone skin, which is a significant advantage for many women. Additionally, silk's anti-static properties enhance comfort.

This underwear set includes both top and bottom pieces with a snug, second-skin fit that allows for comfortable movement. The knitted fabric's elasticity ensures it molds to your body shape, providing an additional layer of warmth under your clothes or serving as cozy sleepwear. The seams and construction appear well-made, helping to maintain the garment’s shape and durability over time.

However, silk generally requires delicate care; the manufacturer recommends using neutral detergent and either gentle machine wash or hand wash, followed by air drying, which might be somewhat inconvenient for those looking for easy maintenance. Silk is also not the best at moisture-wicking and might not perform as well in high-sweat activities compared to synthetic blends. It does offer good breathability, helping regulate body temperature. Odor resistance is moderate; while silk does not retain odors as much as some materials, it isn't as effective as merino wool. This set is ideal for women seeking luxurious, skin-friendly, and warm base layers for everyday cold weather wear or as sleepwear, but might not be the best option for high-intensity activities or those seeking low-maintenance care.