Thank you for your question. Volbella is a great filler for the lines around the mouth. I would recommend starting with 1 syringe and wait at least 2 weeks before reassessing the need for another syringe. It is always smartest to start with less and be able to add more.
I recommend getting a formal evaluation with a facial sculpting expert. These fillers, (Volbella, Restylane, Juvederm) are good to create a symmetrical and full lip. PDO Nova threads can also be used to improve shape and also provide lift. Fat or implants are a permanent alternative. Best, Dr. Emer