the mechanism of action of Sculptra is to encourage collagen formation in a way that allows building volume, allowing us to restore youthful shape to faces. It typically takes 8-12 months to see the final result. The buttock, like the breasts, have shape and volume predominantly due to fatty tissue. A better and less expensive option is the Vampire or PRP (platelet rich plasma) procedure. The final result is typically seen 3-4 months after injection. The cost for Sculptra is going to be expensive because it takes many vials to make a noticeable improvement in the volume of a buttock. Likely 3-5 vials per buttock, (6-10 vials for both) at a cost of $750-$850 per vial, depending where you go. The cost for the Vampire procedure would likely be $1500-$3000 for both buttocks, and likely give you more volume and natural feel than the Sculptra. (And I am telling you this as one of Sculptra’s biggest fans!!!) I hope that helps.