Another significant concern with dermal fillers has
been longevity. The search for fillers that do not
require allergy testing and potentially last longer
than collagen-based products brought about the
development of hyaluronic acid (HA)-based substances.
In December 2003, the first HA product
was approved in the United States (Restylane;
Medicis Aesthetics Holdings Inc., Scottsdale, AZ,
USA), and was soon followed by other HA fillers
(Hylaform, Hylaform Plus, Captique, Juve´derm
Ultra, and Juve´derm Ultra Plus; Inamed
Corporation, now Allergan).