For a looser fit consider sizing up. For women, I am 145 lbs and 5'8 and where a Medium in the women's shirt and love this shirt in a medium as well - a little more room, but great fit.
This t-shirt is everything you've dreamed of and more. It feels soft and lightweight, with the right amount of stretch. It's comfortable and flattering for both men and women.
• 100% combed and ring-spun cotton (Heather colors contain polyester)
• Ash color is 99% combed and ring-spun cotton, 1% polyester
• Heather colors are 52% combed and ring-spun cotton, 48% polyester
• Athletic and Black Heather are 90% combed and ring-spun cotton, 10% polyester
• Heather Prism colors are 99% combed and ring-spun cotton, 1% polyester
• Fabric weight: 4.2 oz (142 g/m2)
• Pre-shrunk fabric
• Side-seamed construction
• Shoulder-to-shoulder taping