This is actually my 3rd time buying this product. I first got it before I had my first body and it really strunk my waist. I then got pregnant and gain a lot of weight so I had to buy a bigger one. Now that I have lost weight my old waist trainer no longer fits so i purchased my third one. Im 5 ft tall and 140 lbs . I got a medium and it fits perfect. A little difficult to put on the first time but it gets eaiser each time. I see results already and its only been 3 days. I would totally recommend to a friend.