10 Best Long Underwear For Women 2025 in the United States

The Cuddl Duds Thermal Underwear for Women is designed to keep you warm during cold weather, featuring a brushed fleece inside for extra coziness. The set includes a thermal shirt top and leggings pants, both made from 93% Polyester and 7% Spandex, which offers a good balance of comfort and stretch. The spandex stretch ensures flexibility and ease of movement, making this set suitable for various activities.

Additionally, the densely knit fabric provides 50+ UV protection, adding an extra layer of safety from harmful rays. The thumbhole sleeve top and modern rise leggings contribute to a comfortable fit that stays in place. However, the heavyweight fabric may not be the best choice for milder temperatures as it could feel bulky. The moisture-wicking feature helps manage sweat by absorbing and evaporating moisture, maintaining dryness. Yet, there is no specific mention of odor resistance, which is a potential downside for those looking for prolonged wear without the smell.

The seams and construction appear durable, enhancing the longevity of the product. This thermal set is versatile enough to be worn as a base layer or on its own, making it ideal for both outdoor activities and lounging at home. Machine washable for easy care, it combines practicality with comfort effectively.

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.

The Merino Wool Base Layer Women Pants are a versatile option for those seeking comfortable and functional long underwear. Made from 100% superfine 17.5 micron Merino wool, these pants promise softness and itch-free wear, which is a significant advantage for sensitive skin. The product offers midweight insulation at 250 g/m², making it suitable for moderate to cold temperatures. This midweight option balances warmth and breathability well, but for extremely cold conditions, you might prefer the heavyweight version (320 g/m²). The inclusion of Merino wool hiking socks is a nice bonus, adding value to the purchase.

The pants excel in moisture-wicking and odor resistance, thanks to the natural properties of Merino wool, keeping you dry and fresh during active use. The pull-on closure design makes them easy to wear, and they are machine washable, though hand washing and air drying are recommended for longevity. While the construction and fit appear to be well-designed for daily comfort, those preferring a more snug or stretchy fit might need to consider other options, as pure Merino wool lacks the elasticity of synthetic blends. The product is made in China, which might be a consideration for those looking for locally manufactured goods.

The need to take extra care while washing is also a minor inconvenience. However, the Merino.tech Promise provides some reassurance for customer satisfaction. These pants are ideal for outdoor enthusiasts and anyone in need of reliable thermal underwear for varying weather conditions.