Effects of the abobotulinumtoxinA with different dilution on the treatment of the upper face

The effectiveness of AbobotulinumtoxinA (BoNT‐ABO) depends on numerous factors, including the amount of dose, presence of autoantibody and number of injected muscles. In this study, we aimed to investigate the effect of the BoNT‐ABO in different dilutions, age groups, and the number of sessions. A total of 60 patients with upper facial wrinkles were included in the study. A 500‐unit vial of BoNT‐ABO was reconstituted with 2.5 mL preservative‐free normal saline for 30 patients and 4 mL saline for the other 30 patients for injection. There was no statistically significant difference between 2.5 mL (4.80 ± 2.08 months) and 4 mL (4.20 ± 1.72 months) group in terms of duration effect of BoNT‐ABO (P = 0.228). There were no significant differences mean duration of effect between the age at ≤40 and > 40 years for each dilutions containing 2.5 and 4 mL. (P = .856, P = .966, respectively). There was no correlation between the number of sessions and the duration of the effect (P = 0.229, C = −0.158). In conclusion, although the difference was not statistically significant, the 2.5 mL dilution of the BoNT‐ABO seems to have a longer effect than 4.0 mL dilution. The low number of sessions of BoNT‐ABO and patients with ≤40 years of age do not have a remarkable longer duration of the effect of BoNT‐ABO.