Efficacy and Safety of Hyaluronic Acid Lip Fillers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Despite the growing demand for hyaluronic acid (HA) lip fillers, there is a paucity of robust, quantitative data across high-powered studies. This systematic review and meta-analysis aims to assess the efficacy and safety of HA lip fillers as reported by randomized controlled trials (RCTs). A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, utilizing PubMed, Embase, and Cochrane, and eligible studies included RCTs with human subjects utilizing HA filler for lip augmentation. Meta-analysis evaluated rates of improvement in lip fullness, aesthetic appearance, patient satisfaction, and adverse events. A comprehensive review initially identified 2,038 articles. Following screening by title and abstract, full-text review, and risk of bias assessment with the Cochrane risk-of-bias tool for randomized trials (RoB 2), sixteen articles were included in the study. Meta-analysis demonstrated that 60% (95% CI: 44-76%) had improvement in lip fullness, 82% (95% CI: 67-92%) had improvement in aesthetic appearance, 68% (95% CI: 58-78%) reported satisfaction, 50% (95% CI: 27-73%) had adverse events, and 1.5% (95% CI: 1.9-4.0%) had serious adverse events requiring treatment, needing follow-up, or lasting beyond 30 days. The most common adverse events were swelling (78%), firmness (48%), bruising (34%), and tenderness (33%). Across studies with the highest level of evidence, HA filler efficacy and patient satisfaction is moderate to high. Severe adverse reactions are rare, but adverse events are common.