Efficacy and Safety of Poly-l-Lactic Acid for Correction of Midfacial Volume Loss and Contour Defects: A Prospective, Multicenter, Randomized, Parallel-Controlled, Evaluator-Blinded, Superiority Trial.

Summary

In a multicenter randomized, assessor-blinded superiority trial (n=331), PLLA outperformed hyaluronic acid for midfacial volume restoration, with higher MMVS and GAIS responses at 6 and 12 months. Safety was comparable, with only slightly increased transient injection-site reactions in the PLLA group.

Key Findings

• Primary efficacy: PLLA achieved higher MMVS efficacy than HA (90.57% vs 51.01%; difference 39.56%, 95% CI 30.34%–48.78%).
• Durability: At 6 months, MMVS 93.04% vs 69.33% and GAIS (investigator) 99.37% vs 86.67%; at 12 months, MMVS 84.91% vs 46.98% and GAIS 94.34% vs 74.50% (all p<0.05).
• Patient-reported outcomes: Satisfaction was higher in the PLLA group (p<0.05).
• Safety: No significant differences in vitals, labs, or overall adverse events; slightly higher injection-site reactions with PLLA resolved in 1–3 days.

Clinical Implications

PLLA can be considered a first-line filler for midfacial volume loss when durability is prioritized, with counseling on mild transient injection site reactions. Follow-up beyond 12 months and comparative data with multiple HA products remain needed.

Limitations

• Assessor-blinded but not fully double-blinded; potential performance/placebo effects cannot be excluded.
• Comparator limited to one HA control; follow-up limited to 12 months.

Future Directions

Longer-term comparative studies versus multiple HA formulations and other biostimulatory fillers, standardized injection protocols, and imaging-based volumetric outcomes will strengthen generalizability and mechanistic understanding.