I need to plump up labia majora. Is Sculptra a good filler?

  Yes, Sculptra is an excellent filler.  That said, to the best of my knowledge there is not so much reported as using it for filling of the labia majora as you are requesting.  Fat is commonly used here.  Alternatively, an HA filler like restylane and Juvederm may be less expensive and may give you the results that you are seeking.

Sculptra is not ideal for the labia majora and its use would be off-label. Fat grafting is an excellent alternative. Best, Dr. Karamanoukian Los Angeles

I find that fat grafting is the best options here and have great success.  However, I have used sculptra, and other hyaluronic acid fillers and they all work well.  The best long term options to maintain the filler is radiofrequency tightening such as Venus legacy or velashape.  I suggest finding a physician with experience in this to treat you as many compliations can occur if not done by a well trained physician.  Best, Dr. Emer.