Safety and Efficacy of Poly‐L‐Lactic Acid Filler ( HYZ vs. Löviselle) Injection for Nasolabial Fold Correction: A Double‐Blind, Non‐Inferiority, Randomized, Controlled Trial

Background Poly‐L‐lactic acid (PLLA) is an established soft‐tissue filler for correcting nasolabial folds (NLFs), offering durable results and high patient satisfaction. This study evaluated the efficacy and safety of a novel PLLA filler (HYZ) for this indication. Methods In this prospective, multicenter, randomized, double‐blind, non‐inferiority clinical trial, 176 subjects were randomly assigned to two groups, were randomized to receive three sessions of either HYZ (experimental group) or Löviselle (control group) injections at 3‐week intervals. Efficacy was assessed using the Global Aesthetic Improvement Scale (GAIS) and the Wrinkle Severity Rating Score (WSRS). Safety was evaluated based on adverse events (AEs). Results From baseline to Week 54, the HYZ group consistently showed higher WSRS response rates than the control group. At Week 54, the response rate was significantly higher in the HYZ group (54.02% vs. 36.36%, p < 0.05), meeting the predefined non‐inferiority margin (Δ = −10%). No significant between‐group differences were observed in GAIS response rates. The incidence of adverse events was comparable between the two groups. Conclusion The novel PLLA filler (HYZ) was non‐inferior to the established product Löviselle in both efficacy and safety for NLF correction. These findings provide new clinical evidence supporting the continued development and optimization of PLLA‐based fillers.