This was a monocentric, prospective, randomized and double-blind study. Fifty nine female patients, presenting with moderate to severe forehead wrinkles, with sweating ability who had never undergone previous BoNT-A injections were enrolled. There were two randomizations, one related to the dose-equivalence (2:1U and 2.5:1U), both reconstituted in the same volume of 0.02 mL per point and another related to the forehead side (left or right) for application of the tested drugs. Baseline, twenty-eight and 112 days later, clinical and photographic assessments, Minor´s test, and electromyographic (EMG) evaluations were performed.