Efficacy of Subdermal Poly-<sc>d</sc>,<sc>l</sc>-Lactic Acid Injections for the Treatment of Melasma

Background: Melasma is a chronic, recurrent skin disorder with limited long-term treatment success using conventional therapies like hydroquinone and laser treatments, which primarily target epidermal components while leaving dermal aspects untreated. Objective: To evaluate the efficacy and safety of poly-d,l lactic acid (PDLLA) subdermal injections for treating moderate melasma. Methods: Three female patients (age range: 45-59 years) with Fitzpatrick skin types III and IV received three PDLLA injection sessions at 3-week intervals. Treatment outcomes were assessed using the Melasma Area and Severity Index (MASI) and patient satisfaction scores at 12-week follow-up. Results: All patients showed significant MASI score improvements (reduction range: 3.60-6.30 points). Patient satisfaction ratings ranged from 3 to 4 out of 4. Temporary side effects included mild edema and bruising, resolving within 72 h. Conclusions: PDLLA subdermal injections showed promising results in melasma treatment, potentially due to its biostimulatory effects on collagen production and dermal remodeling. Further research, including histopathological analysis, is needed to confirm long-term efficacy and safety, and understand underlying mechanisms.