Well, we don't have all the answers but it is a great product (the safest of all fillers; over 5 years- permanent duration-) that maybe didn't get ideal marketing.
Dr. Hamilton has had long term (over 10 years) experience with Bellafill, having published in a medical journal the report of the first 20 patients treated in the US with its early formulation, Artecoll/Artefill. He also was one of the FDA investigators involved in the final phase 3 study yielding its approval. As one of the authors in a five year follow up analysis, he helped make the medical community aware of Bellafill's duration (minimum of 5 years) and safety. Dr. Gottfried Louperle, Bellafill's inventor, was present when Dr. Hamilton was filmed treating patients in order to provide a training guide for other physicians.
In our long experience with this filler, which ultimately fills mainly with the patient's own natural skin collagen, we have seen no side effects. Indeed, Bellafill is the only filler where a skin test is done (because it is of 5 year duration); we have had only one positive test in over 10 years of use.