The buttocks and hips can be volumized and contoured by safely injecting fillers, which are made up of hyaluronic acid. In order to fill and improve the shape, a significant amount of hyaluronic acid is injected into the affected area. Hyaluronic acid is safely reabsorbed by the body after two to four years. Depending on the volume of hyaluronic acid used, the results may not be as dramatic as fat transfer surgery or butt implants; however, if a good amount of volume is used, obvious results are seen immediately, and the results get much better over time. This procedure can take 1 hour or more, depending on the amount of filler being used.