# Long-Term Correction of Nasolabial Folds Using Poly-L-Lactic Acid Microspheres: A Multicenter, Double-Blinded, Randomized Trial

## TL;DR

A study compared PLLA microspheres and HA fillers for correcting nasolabial folds, finding PLLA provides longer-lasting results but requires more initial treatments.

## Contribution

Demonstrates that PLLA microspheres offer durable correction of nasolabial folds over 48 weeks compared to hyaluronic acid.

## Key findings

- PLLA showed a 92.4% effective correction ratio at 48 weeks versus 59.3% for HA.
- PLLA required more early treatments but provided sustained improvement from week 36 onward.
- Adverse events were mild and transient in both groups.

## Abstract

Correction of moderate-to-severe nasolabial folds (NLFs) is a key concern in aesthetic medicine. Poly-L-lactic acid (PLLA) microspheres, with biostimulatory properties, potentially offer longer-lasting results compared with hyaluronic acid (HA), the current standard of care.

The aim of this study was to evaluate the efficacy and safety of PLLA microspheres vs HA for the correction of moderate-to-severe NLFs.

In this multicenter, randomized, double-blind, parallel-controlled trial, 252 participants were enrolled across 8 centers in China and assigned to receive either PLLA or HA filler. The primary endpoint was the effective correction ratio of the Wrinkle Severity Rating Scale (WSRS) at 48 weeks, assessed by blinded independent reviewers. Secondary endpoints included WSRS change, Global Aesthetic Improvement Scale (GAIS) scores (investigator- and participant-assessed), treatment frequency, and safety outcomes.

At 48 weeks, PLLA demonstrated a significantly higher effective correction ratio than HA (92.4% vs 59.3%; difference, 33.1% [95% CI, 23.1-43.2]; P < .0001). HA outperformed PLLA at Week 4, reflecting its immediate effect, whereas PLLA showed superior outcomes from Week 36 onward with sustained improvement confirmed by WSRS and GAIS. PLLA required more frequent early treatments, whereas HA generally achieved correction with fewer sessions. Adverse events were mild and transient, with no serious complications in either group.

Under current protocols, HA offers rapid improvement, whereas PLLA requires multiple early sessions but yields more durable correction up to 48 weeks with similar safety. Filler selection should be individualized according to patient priorities.