The Under Armour Women's ColdGear Authentic Base Leggings are a top-rated choice for women's Lycra base layer bottoms on Amazon. These leggings are made with a blend of polyester and elastane, providing a comfortable and stretchy fit. The ColdGear technology helps to keep you warm and dry, making them perfect for cold weather activities. With a wide waistband and a compression fit, these leggings offer support and a flattering silhouette. They are available in various sizes and colors to suit your preferences.