Sculptra is an excellent facial filler for restoring or increasing volume in a multitude of areas of the face. I commonly use it for the upper and lower portions of the cheeks, the temples, the jawline, the nasolabial folds, and the marionette lines. However, Sculptra should not be used in the lips, as the risk of lumps or bumps would be quite high. You should also avoid permanent fillers such as silicone in the lips.
For lip augmentation, there are a number of better alternative fillers, such as Juvederm, Restylane, and Perlane. These fillers can be used much closer to the surface of the skin and have the additional of being dissolvable, if you don't like the effect or develop a lump or irregularity.
Overall, the lips are a very rewarding area to inject as patient satisfaction is typically very high. The key is to inject a conservative amount of filler in the right places, to avoid that overdone, "ducky" look.
Best,
Dr. Mehta