A Randomized, Double‐Blind, Multicenter Comparison of the Efficacy and Tolerability of Restylane Versus Zyplast for the Correction of Nasolabial Folds

Patients and investigators judged hyaluronic acid gel to be more effective in maintaining cosmetic correction and nonanimal stabilized hyaluonic acid provides a more durable aesthetic improvement than bovine collagen and is well tolerated.