I picked this up after a back injury as the other medical back supports were lacking in size for my hips and non-metal support. I have to clear a metal detector at work, so typical back supports were out of the question, while the WalGreen's lower back support brace did well and didn't go off, it did ride up off my hips while sitting and didn't offer support low enough for my pulled muscles in my lower back. I was looking at other traditional back supports when one reviewer mentioned an old fashioned girdle was more supportive than the medical one she was given. That got me to thinking. I also needed something to go down low enough on my hips for the support but not so much support that the rest of my torso was squished. I opted for the 3X size since if I was purchasing this product for slimming, the 1X would have been right, but the measurements for my lower hips were on the upper end of 1X and I wanted comfort as well as support. This shaper comes with little straps to attach to your bra to keep it from rolling down. Here is the but, I have a long torso and this one, in this size, is a bit longer than I had thought, but that works well for covering my hips for support. Shorter torsoed people may need to consider this length difference when ordering a size up, as the next size up also expects to take up more space in the around/circumference part making it fit the torso better. This is like going up a size in pants only to find you don't have enough tummy pooch to fill out the stride from the waist to the crotch of the pants resulting in a bunching/gathering of fabric at the crotch. I wanted something to support my lower back and not set off the metal detector at work, and that is what I got. If you want slimming, this will do it as well to smooth out those bumps, but do not order a size up because you will not get the smoothing you will get if you order by measurements. The size chart is:Small 4-6 Bust:33.5"-35.5" Waist: 26.5"-28" Hip: 36"-37.5"Medium 8-10 Bust: 36-38 Waist: 28.5-30.5 Hip: 38-40.5Large 12-14 Bust: 38.5-40.5 Waist: 31-33 Hip: 41-43XL 16-18 Bust: 41-43 Waist 33.5-35.5 Hip 43.5-45.51X 18-20W Bust: 44-47.5 Waist: 36-39 Hip: 46-49.52X 22W-24W Bust 48-51.5 Waist 39.5-43 Hip: 50-53.53X 26W-28W Bust:52-54 Waist: 43.5-45.5 Hip: 54-56You need to size based on measurement and not your store size. Also take the measurement of your largest area to determine the best size for you as that area will be squeezed the most if you order based on the smaller measurements. I measured a Hip of 53" around the fullest part of my bum, so I could get the lower back support I needed, so to make sure I could flex and be comfortable for 12 hours, I sized up one. Take your measurements carefully and do not be stunned by your size in this and similar garments or you will be unhappy and get your fit wrong.Edited 06/29/2013: I received the size 1X and have been wearing it to work. This one does support my lower back as it does go down over the hips. I haven't had an issue with rolling as long as I use the straps that attach it to the bra, which are awesome. It is not difficult to get on by stepping into it and pulling over my hips and bum. The fabric is soft and smooth on my skin and doesn't itch even when I running around work and get sweaty. My back doesn't seem as sore at the end of the day from the extra compression support on my muscles which increases blood flow like my compression stockings do. When you work long hours on concrete you need all the support you can get!Even though the shaper comes with straps to keep it from rolling down, they were too small to be functional with my bra. I wear a 38DD, and the front and sides of my bra were too wide to be able to utilize the straps. As such, the shaper rolled down. I still wore it for my event, but it did roll down, especially in the back, ~1 - 1 1/2 inches.Very long. Bottom rolled up and top I think would roll even if attached to the bra just because it was to longI don't like how it rolls up from the bottom. Other than that it stays in place.It is too long, even the small one. Maybe it meant to cover the hips as in the pic! Not much of shaping, rather you will use it to keep you warm in winter.This fits like a fitted tube top. i went according the size chart, I bought a medium. It held nothing it, was obvious at the hips and too long. What a waste.Great to hold in those problem areas.it does as described. i love the optional bra attachments to keep the shaper from rolling down. it fits a little tight.