The number of Botox units used for the glabella is typically higher than for crow’s feet due to stronger muscles between

https://www.scribd.com/document/984678840/The-Science-of-Onset-Why-Forehead-Responds-Faster-Than-Masseter-181603

The number of Botox units used for the glabella is typically higher than for crow’s feet due to stronger muscles between the eyebrows causing deep frown lines.