A BBL may be possible after prior buttock filler in some cases, but it depends very much on what was injected, how much was used, and where it was placed. The photos show your overall contour, but they cannot tell us the product type or depth. Hyaluronic acid filler is very different from silicone, PMMA, biopolymer, or an unknown product. Fat grafting into tissue that already contains permanent or unknown filler can be less predictable and may increase risks such as inflammation, infection, nodules, contour irregularity, fat necrosis, or difficulty judging safe fat placement. Before planning a BBL, try to obtain the exact product name and injection records. An in-person evaluation with a plastic surgeon experienced in buttock surgery is important, and imaging such as ultrasound or MRI may help map the material. If the filler is permanent or unknown, many surgeons will be cautious or may advise against adding fat until the risks are clearer.