These were one of the first leggings I tried from born primitive. I love them. I've been wearing another brand mostly, but I'm sure I'm replacing the majority of them now😂. I'm kind of a smedium sometimes at 5'6", 145ish, 27ish" waist, 39ish" hips. I bought a small. A medium would have fit well, too, but I worried I'd prefer a smaller size because I saw many people say they're *very* stretchy. I was not misinformed. I'm glad I sized down even though they are a bit thin. They feel like you're not wearing pants, honestly. My husband hasn't said he's noticed them being see-through yet with nude undies (as of now, probably 3 wears), so that's good. I would probably not size down in the lighter colors (I got navy). With the smaller size, the scrunch detail on the back isn't as noticeable, but I think I prefer that. It's not my favorite trend🤷🏼♀️. The texture is amazing and, girl, does it hide cellulite! I know it's normal, but there's just something about feeling yo'self that makes for some great workouts. Please restock these often. I love them and need a few backup pairs.