Restylane is the trade name for a range of injectable fillers with a specific formulation of non-animal sourced hyaluronic acid (HA). Restylane is the trade name for a range of injectable fillers with a specific formulation of non-animal sourced hyaluronic acid (HA). In the United States, Restylane was the first hyaluronic acid filler to be approved by the U.S. Food and Drug Administration (FDA) for cosmetic injection into subdermal facial tissues.