Prospective Evaluation of Cross-linked Sodium Hyaluronate Gel for Injection in Treating Moderate-to-Severe Nasolabial Folds: A Randomized Controlled Evaluator-Blind Non-inferiority Study

INTRODUCTION: This study evaluates a novel lidocaine-premixed hyaluronic acid (HA) gel for nasolabial fold (NLF) correction, addressing pain management and longevity challenges in facial rejuvenation. The aim is to assess the non-inferiority, efficacy, and safety of this investigational HA gel versus an established comparator. METHODS: In this multicenter, evaluator-blinded randomized controlled trial (RCT), 324 Chinese adults with moderate-to-severe NLFs (Wrinkle Severity Rating Scale [WSRS] 3-4) received either test product (22 mg/mL HA + 3 mg/mL lidocaine) or control. The primary endpoint was ≥ 1 grade WSRS improvement at 6 months. RESULTS: The test product showed non-inferiority at 6 months (full analysis set [FAS]: 88.27% versus 85.19%, P = 0.392; per‑protocol set (PPS): 91.45% versus 88.24%, P = 0.363), with 95% confidence intervals (CIs) exceeding a -10% margin. Pain scores were comparable at 0.5 h/1 h post-injection (P > 0.05) but higher at 2 h post-touch-up (P < 0.05). Adverse event (AE) rates were similar, with induration/swelling being most common. CONCLUSIONS: The lidocaine-premixed HA gel is non-inferior for NLF correction, offering similar safety and efficacy with integrated anesthesia.