Onset and Duration of AbobotulinumtoxinA for Aesthetic Use in the Upper face: A Systematic Literature Review.

We sought to analyze the current literature regarding time to onset and duration of effect of abobotulinumtoxinA (aboBoNT-A, Dysport®/Azzalure®) for upper facial aesthetic indications. We conducted a systematic review of literature databases (PubMed/MEDLINE, Embase, Cochrane Library, and Google Scholar) to identify English-language publications relevant to: population (patients with aesthetic indications [including glabellar lines and wrinkles]); interventions (aboBoNT-A); comparators (no restrictions); outcomes (efficacy, including onset of action and duration of effect); and settings (clinical). A manual search of review paper bibliographies was performed. Structured data extraction was used to enable interstudy analysis. Overall, 42 original research papers relevant to aboBoNT-A onset and/or duration were identified. All 24 studies assessing efficacy within one week post-injection demonstrated some response at the first time point assessed, and all 37 studies assessing duration showed some response after 12 weeks. Although methodologies for assessing onset and duration differed, when outcomes were refined by reported mean/median, at least 50 percent of patients responding to treatment, or significance versus placebo or baseline at a given time point, onset was most often reported within 2 to 3 days (7 studies), and as early as 24 hours (2 studies). Duration was most often reported as four months (18 studies), although four studies provided evidence that aboBoNT-A efficacy was maintained at five months and three studies at or after six months post-injection. This review indicates that aboBoNT-A has a median onset of efficacy of 2 to 3 days and a longer duration of action (3-6 months across studies) than the current labelled minimum treatment interval (12 weeks).