Impurities in Hyaluronic Acid Dermal Fillers? A Narrative Review on Nonanimal Cross-Linked Fillers

Nonanimal cross-linked hyaluronic acid (HA) dermal fillers are among the most versatile tools in minimal invasive esthetic medicine. Filler injections aim to volumize, provide contour, and reduce wrinkles and skinfolds. In the hand of the experienced user, HA fillers have an excellent safety profile. Nevertheless, adverse events have been reported related to poor injection techniques, infection, and immune reactions.