Poly-L-lactic acid injections stimulate skin rejuvenation over time

Key takeaways:

• The treatment group saw a 1.34-point increase in global aesthetic improvement scale score at the 18-week follow-up.
• Treated skin exhibited morphologic changes consistent with the process of skin rejuvenation.

Histological evaluations showed poly-L-lactic acid injections stimulate skin rejuvenation over time, according to a study.

“Some fillers, such as hyaluronic acid, volumize the area of injection instantly,” Suleima Arruda, MD, of Sadick Dermatology and Research, and colleagues wrote. “Others, such as poly-L-lactic acid (PLLA), are biostimulatory, meaning that they activate resident fibroblasts to produce autologous collagen over time. This leads to a more natural and long-lasting effect.”

Approved in 2023 for the treatment of fine lines and wrinkles in the cheek region, PLLA injection has been used off label for many other areas such as the abdomen, gluteal region and chest. The observable improvements of PLLA injection are well known, but a gap in knowledge is present for a histological explanation of these results. To bridge this gap, the authors conducted a randomized, placebo-controlled, single-center study.

In the study, 10 healthy women (age range, 30-65 years; Fitzpatrick skin types I-IV) were randomly assigned to receive three PLLA or saline injections every 4 weeks with a follow-up appointment occurring 18 weeks after the last treatment.

At the follow-up, investigators observed a 1.34-point increase on the global aesthetic improvement scale among the PLLA group vs. no increase in the saline group. All seven patients in the PLLA group also reported a 1-point or greater improvement on the global aesthetic improvement scale.

According to histological findings, there was no filler found at the final follow-up, meaning the filler likely dissolved during tissue processing. PLLA-treated skin did not show any signs of inflammation or damage; however, it did show more formulated capillaries compared with saline-treated skin. This may indicate that PLLA stimulates vascularization.

Additionally, PLLA-treated skin exhibited morphologic changes consistent with the process of skin rejuvenation such as decreased elastin fragmentation and increased tissue remodeling, whereas the saline-treated group did not.

“The results presented herein demonstrate that repeat treatments of PLLA improve skin quality by stimulating dermal remodeling processes in the tissue over time,” the authors concluded.