Women’s merino wool base layers from Icebreaker are the perfect way to stay comfortable during any activity. Wear them on a trail run, under your cycling kit, or in the backcountry. Our wool base layers are an integral part of our signature merino wool layering system. We use only the finest, natural merino wool to ensure that you have the most comfortable, lightweight and moisture-wicking material out there. Merino wool provides superior temperature control, no matter the conditions. Breathable for warm weather, and insulating for cold—this material does it all. Shop our full collection of women’s base layers including short sleeve, long sleeve, and leggings. These women’s base layers also go great with our selection of accessories that are specially designed to help you through even the most rugged terrain. Check out our sports bras and underwear to complete the perfect layering system.