“…This might not be a drug-related effect but could instead be due to variability of the clinical scoring method used, and this weakens the conclusions of Lowe and colleagues substantially. 23 According to a Phase II Food and Drug Administration trial of Dysport in the treatment of glabellar lines, a dosage of as low as 20 U is effective in most cases, supporting a unit equivalence of 2.5:1. , Karsai et al 21 , Monheit et al 24 , Ascher et al 26 , Rzany et al 29 , Ranoux et al 31 , Odergren et al 33 , Poewe et al 34 , Simonetta-Moreau et al 38 , Talarico-Filho et al 40 , Wohlfarth et al 43 IIa SR of cohort studies (CS) with homogeneity Sesardic et al 9 , Poewe, 32 Rosales et al 45 IIb Individual CS or low-quality RCT Bihari, 16 Lowe et al 22 , Brisinda et al 35 , Sampaio et al 36 , Nü Xgens and Roggenkä mper, 37 Trindade de Almeida et al 39 , Hexsel, 41 de Almeida et al 42 IIc ''Outcomes'' research Marchetti et al 17 , Heckmann and Schö n-Hupka, 25 Van den Bergh and Lison, 44 Rosales et al 45 V Expert opinion Hambleton and Pickett, 7 Rzany and Zielke, 11 Sommer et al 20 SR, systematic review; RCT, randomized controlled trial; CI, confidence interval; CS, cohort study.…”