I purchased a medium after discussing it with the staff. At first I open the package and I was skeptical because it seemed smaller than the other bikini briefs that I had purchased But this was a thong. So I tried it on and I was pleasantly surprised that it conforms to my body. I will write all day the day before yesterday and I was like I was wearing nothing. With the typical thong I would always experienced pain with in 5-6 hour of wear but with these no pain at all. Wish the came in more colors and prints! All my friends at the locker room want to know more about this product. I happily sent them to your site. Happy shopping!