During the procedure, there should be no pain whatsoever for you. This is because, during the Brazilian Butt Lift surgery, you will be placed under some form of general anesthesia or sedative, not only to make the process utterly painless for you but also to make the whole experience as stress-free as possible.
However, during your recovery and healing time post-surgery, be prepared for some level of manageable pain, as any surgery of this sort will undoubtedly bring some discomfort. But don't worry—the pain will diminish quickly with a little bit of time and the help of some over-the-counter pain medications.