Advances in Poly-l-lactic Acid Injections for Facial and Neck Rejuvenation

Background: Poly- l -lactic acid (PLLA) has gained popularity as a cosmetic injectable filler due to its excellent biocompatibility and capacity for long-term collagen stimulation. Despite widespread clinical use, a comprehensive evaluation of recent advancements and updated clinical techniques is essential for improving facial rejuvenation outcomes and minimizing complications. Methods: A comprehensive literature review was conducted through databases including PubMed and Web of Science. We analyzed recent advancements, clinical efficacy, safety profiles, injection techniques, and comparative advantages of PLLA relative to other fillers. The review emphasized clinical trial outcomes, practical injection recommendations, and management strategies for common and rare complications. Results: Recent clinical studies confirmed the effectiveness of PLLA in treating facial wrinkles, volume loss, and enhancing skin elasticity and hydration, with patient satisfaction exceeding 90%. Novel injection techniques such as ultrasound guidance and needle-free microjet injection have improved safety and patient satisfaction. Technological innovations, including particle-size optimization and composite formulations, have further enhanced the biocompatibility, efficacy, and duration of effect of PLLA, significantly reducing adverse events. Conclusions: PLLA injections offer safe, long-lasting, and natural rejuvenation outcomes for facial and neck areas. Continuous innovation in injection technologies, particle formulations, and combination therapies promises further enhancements. Future research should focus on individualized treatment protocols, optimizing long-term safety and efficacy, and expanding PLLA applications through advanced biomaterials and regenerative approaches.