Beyond Wrinkles: A Systematic Review and Meta-analysis of Off-Label Aesthetic Uses of Botulinum Neurotoxin.

[BACKGROUND] Many popular botulinum neurotoxin treatments are off-label, yet no review has comprehensively captured their effects. This study provides a systematic review of neurotoxin's off-label aesthetic applications, focusing on muscle targets, aesthetic goals, outcomes, and patient satisfaction.

[METHODS] A systematic review of PubMed, MEDLINE, and Web of Science was conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Eligible studies were published between 2014 and 2024, describing nonwrinkle aesthetic uses of botulinum toxin type A in adults. Data extracted included patient demographics, muscle targets, aesthetic goals, procedural approaches, outcome measures, and patient satisfaction. Proportion meta-analyses were performed using Stata software.

[RESULTS] Of 531 search-identified studies, 38 met inclusion criteria, totaling 1903 patients aged 17 to 93 years. Patients were primarily female (94.3%, P < 0.0001), with a mean age of 43.7 years. Most interventions targeted the lower face (70.3%, P < 0.0001). Facial aesthetic goals included eyebrow lift, forehead fat graft retention, nasal flare reduction, nasal tip sculpting, facial slimming, and correction of gummy smile, downturned mouth, chin retrusion, mentalis strain, and lower-face descent. Nonfacial aesthetic goals included neck, arm, and calf contouring and scrotal relaxation. Interventions focused on reducing volume/bulk (n = 21, 61.8%) or reshaping (eg, lifts and smile correction) (n = 16, 47.1%). Overall satisfaction was high (94%; 95% confidence interval, 88%-98%). Studies with quantitative measurements during the first follow-up (n = 23) reported sustained results (75.0%, P < 0.0001), with minimal reported complications.

[CONCLUSION] Beyond rhytid reduction, botulinum toxin type A demonstrates versatile aesthetic utility in facial and body contouring, with high patient satisfaction and minimal adverse effects. Standardized protocols and refined evaluation methods are needed to inform decision-making, expand clinical guidance, and optimize outcomes.