Comparison 16. OnabotulinumtoxinA 40 units versus 20 units one treatment glabellar lines.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
16.1 Participant assessment of success by analysing scores and scales	2		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
16.1.1 4 weeks	2	80	Risk Ratio (M‐H, Random, 95% CI)	1.63 [1.13, 2.35]
16.1.2 8 weeks	2	80	Risk Ratio (M‐H, Random, 95% CI)	1.52 [0.77, 2.97]
16.1.3 16 weeks	2	80	Risk Ratio (M‐H, Random, 95% CI)	2.51 [0.88, 7.16]
16.2 Physician assessment of success by analysing scores and scales	2		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
16.2.1 4 weeks	2	80	Risk Ratio (M‐H, Random, 95% CI)	1.48 [0.93, 2.36]
16.2.2 8 weeks	2	80	Risk Ratio (M‐H, Random, 95% CI)	1.35 [0.82, 2.23]
16.2.3 16 weeks	2	80	Risk Ratio (M‐H, Random, 95% CI)	1.34 [0.51, 3.53]
16.3 Total adverse events	2	80	Risk Ratio (M‐H, Random, 95% CI)	1.93 [0.53, 7.05]