[Efficacy and safety of injectable sodium hyaluronate gel in correcting moderate to severe nasolabial folds: a single-center, randomized, double-blind, controlled trial].

OBJECTIVES

To evaluate the 12-month clinical efficacy and safety of Dr. Korman® injectable cross-linked sodium hyaluronate gel (DKL) in correcting moderate to severe nasolabial folds.

METHODS

This was a single-center, prospective, randomized, double-blind, parallel-controlled trial. A total of 80 subjects with moderate to severe nasolabial folds (Wrinkle Severity Rating Scale [WSRS] score 3-4) were enrolled at Tongde Hospital of Zhejiang Province from October 2022 to June 2025 and assigned 1∶1 to the trial group (DKL) or the control group (Restylane® 2), with 40 cases each. Both groups received a layered injection strategy using a sharp needle for the periosteal layer and a blunt cannula for the subcutaneous fat layer. Subjects who failed to achieve a WSRS score reduction of ≥1 point at 1 month post-injection received a supplementary injection. Efficacy was evaluated using the WSRS and Global Aesthetic Improvement Scale (GAIS) at baseline and at 1, 3, 6, and 12 months after treatment. Local reactions and adverse events were recorded throughout the study. The primary efficacy endpoint was the bilateral WSRS score at 12 months post-injection. Equivalence was tested using two one-sided t-tests (TOST), and clinical relevance was assessed with Cohen's d effect size.

RESULTS

Baseline characteristics-including age, sex, nasolabial fold severity, and injection volume-were balanced between two groups (all P > 0.05). Both groups showed significant improvements in WSRS and GAIS scores at all follow-up time points compared with baseline (all P < 0.01), with no statistically significant intergroup differences at any time point (all P > 0.05; Cohen's d < 0.2). At 12 months, the between-group difference in WSRS score was ≤0.02 points (95% CI: -0.21 to 0.23), and both one-sided tests of the TOST yielded P < 0.05, confirming statistical equivalence. GAIS results indicated that efficacy in the trial group peaked at 1-3 months, with a mild decline in improvement at 6 months; scores at 12 months remained significantly better than baseline (all P < 0.01; Cohen's d > 0.5), demonstrating stable maintenance of clinical improvement for 12 months. Regarding safety, there were no significant differences between groups in the incidence of expected physiological local reactions (all P > 0.05). No serious adverse events occurred during the 12-month follow-up. The overall adverse event rates were 7.50% in the trial group and 10.00% in the control group, with no significant difference (P > 0.05); all events resolved spontaneously.

CONCLUSIONS

DKL is equivalent to Restylane® 2 in 12-month efficacy and exhibits a favorable safety profile for correcting moderate to severe nasolabial folds, offering a new option for minimally invasive filling correction in clinical practice.