Background: Although botulinum toxin type A (BoNT-A) is a common aesthetic intervention, there are few published data on treatment over more than two cycles.
Objective: To evaluate the effectiveness/safety of repeated doses of BoNT-A (Dysport, Ipsen Ltd., Slough, UK) in the upper face for reduction of wrinkles.
Methods: Retrospective, cross-sectional patient chart review from 945 patients who had received a minimum of three consecutive, documented treatment cycles.
Results: The glabella was treated most frequently (93.9%), with the majority (81.5%) of patients receiving treatment in more than one area of the face. BoNT-A treatments were combined with other aesthetic procedures in 57.5% of cases, mostly with fillers (37.1%). There was no evidence of tachyphylaxia: the dose applied, the interval between treatments, and satisfaction with the results remained stable over the course of treatment. Adverse events were those expected with BoNT-A treatment (most common: local bruising and ptosis) and were all mild or moderate in intensity. There was no sign of any cumulative adverse effects: indeed, the adverse-event rate decreased in later treatment cycles.
Conclusions: Long-term, repeated injections of BoNT-A for corrections of wrinkles in the upper face yield a continuously high level of safety and effectiveness in actual practice.