This is different for everyone as each individual will experience waist training differently. We strongly recommend purchasing two waist trainers at one time as you will most likely go down in size within 1-2 months. By purchasing two at a time you will receive a discount and you will have the smaller size ready for you as soon as you need it! Typically, your waist will shrink fastest in the beginning, some people go down a size within one week to one month. As you become smaller it tends to take longer to lose the last 1-2 inches from your waist. This is common with general weight loss as well, you have heard the expression, "The last 10lbs is the hardest to lose".