The answer to this question is two fold since there are actually 2 questions in 1 here. Regarding HIFU after threads, I would not recommend it because most threads are place in subdermal or subcutaneous tissue and often at times at the depth of the skin where the HIFU will be transmitting energy to. Theoretically it could metabolize the threads faster that what you would like. Regarding HIFU after fillers, that is probably acceptable as long as the fillers was placed in a deep plane such as down to the periosteum or bone. The HIFU does not deliver energy to that depth. If the fillers were placed more superficially then yes the HIFU can metabolize the fillers. Hope this helps. TJ Tsay MD Ageless MD