Efficacy and Safety of PrabotulinumtoxinA for the Treatment of Moderate to Severe Glabellar Lines: A GRADE Assessed Systematic Review and Meta-Analysis

Abstract Glabellar lines are among the earliest and most visible signs of facial aging and can convey negative emotions while diminishing quality of life. PrabotulinumtoxinA is a 900-kDa formulation of botulinum toxin type A that provides targeted neuromuscular blockade to treat dynamic wrinkles through localized muscle relaxation. Individual trials have reported encouraging results, yet pooled estimates were needed to more accurately quantify efficacy and safety. The objective of this meta-analysis was to evaluate the efficacy and safety of prabotulinumtoxinA for the treatment of glabellar lines. We searched PubMed, Cochrane CENTRAL, Scopus, Embase, and ClinicalTrials.gov through May 2026 and identified three double-blind, placebo-controlled phase III randomized controlled trials evaluating a 20 U dose of prabotulinumtoxinA versus placebo; three additional studies were included for qualitative safety analysis. In pooled random-effects analyses, prabotulinumtoxinA significantly increased the likelihood of achieving none-or-mild glabellar line severity scores (GLS score 0/1) at Day 30 (RR = 19.24, 95% CI 12.08–30.64; p < 0.01), demonstrated early treatment response at Day 2 (≥1-point improvement in GLS score: RR = 3.61, 95% CI 2.52–5.19; p < 0.01), and showed greater sustainability through Day 150 (RR = 3.47, 95% CI 2.13–5.65; p < 0.01). Safety outcomes, including treatment-emergent adverse events (TEAEs) and specific safety endpoints, were comparable to placebo, with no significant differences. PrabotulinumtoxinA was well-tolerated and produced substantial and sustained improvement of glabellar lines. Further large-scale, long-term trials are needed to establish its durability and long-term safety profile.