Dear Dr.Harrydoll2019, most patients will lose 30-50% of transferred fat after the surgery. Fat viability depends a lot of surgeon technique. The fat has to be placed back into the buttocks as soon as possible so that it has a greater chance of survival. It has to be placed carefully so that not too much fat is placed in only one area. If you are considering a surgery, I would suggest you to consult a board-certified plastic surgeon. Only after a thorough examination you will get more information and recommendations. Daniel Barrett, MD Certified, American Board of Plastic Surgery Member, American Society of Plastic Surgery Member, American Society of Aesthetic Plastic Surgery