Repeated Botulinum Toxin A Injections for the Treatment of Lines in the Upper Face: A Retrospective Study of 4,103 Treatments in 945 Patients

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.