Comparison of Botulinum Toxin A Formulations for Glabellar Strain Treatment in Women: A Double-Blind Randomized Clinical Trial.

Summary

In a randomized, double-blind trial (n=143), abobotulinumtoxinA and prabotulinumtoxinA achieved the fastest onset (day 3). At 180 days, prabotulinumtoxinA and incobotulinumtoxinA retained significant efficacy vs baseline, with prabotulinumtoxinA outperforming onabotulinumtoxinA. Greater baseline strain predicted greater improvement, and lateral canthal strain increased as glabellar strain decreased.

Key Findings

• ABoNT/A and PBoNT/A showed the fastest onset by day 3.
• PBoNT/A and IBoNT/A retained significant efficacy at day 180 vs baseline.
• PBoNT/A was significantly more effective than OBoNT/A at day 180.
• Higher baseline glabellar strain predicted greater post-treatment improvement.
• Lateral canthal strain increased as glabellar strain decreased; FACE-Q scores improved up to 90 days in all arms.

Clinical Implications

Clinicians can tailor product choice: ABoNT/A and PBoNT/A for rapid onset; PBoNT/A or IBoNT/A for longer-lasting effects near 6 months. Monitor compensatory strain in the lateral canthal area and counsel on expected durability and satisfaction timelines.

Limitations

• Single-center, female-only cohort limits generalizability.
• Assumptions inherent in unit equivalence across toxin brands; not powered for detailed safety comparisons.

Future Directions

Multicenter trials including male and diverse populations; harmonized dosing equivalence studies; longer-term durability and safety; integrated assessment across adjacent aesthetic units.