Repetitive filler injections creating collagen
There is now fairly good scientific evidence and experience showing that fillers over time appear to last longer or the effect they give seems to last longer, and it is believed to be due to stimulation of one's own inherent collagen production.
The only filler that properly stimulates collagen is Artesense or Artefil. But it must be used quite precisely and in multiple layers to accomplish a good r result. Juvederm like fillers will NOT create collagen but they can last up to a year in that location.