Why is fat transfer for lips not as popular as fillers?

Fat transfer is a fantastic option for many areas of the body. It also looks great in the lips. However, since fat is designed to be a live graft that will last for many years, the blood supply to the fat is essential for a long life. When fat is placed into the lips, the active movement of talking, smiling and laughing makes it difficult for the blood supply to attach to the graft and then it fails or should I say it dissolves slowly over a 5-6 month period. For that type of duration - other fillers are just as viable alternative.

Fat grafting to the lips can give a very beautiful, natural looking and permanent result. I often add fat to the lips when I am performing facial rejuvenation surgery. However, The downtime with fat to the lips is somewhat significant.  If someone wants fullness only to the lips, it is hard to justify the downtime when other great and long lasting fillers are available that require very limited downtime. For other parts of the face, nothing compares to fat.