Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Adverse effects
RCT	276 people, aged 18 years or over, with moderate to severe glabellar frown lines at maximum frown (score of 2 or 3 on the Facial Wrinkle Scale)	Adverse effects 13/184 (7%) with incobotulinumtoxin A 2/92 (2%) with placebo	Significance not reported
RCT	271 people, aged 18 years or over, with moderate to severe glabellar frown lines at maximum frown (score of 2 or 3 on the Facial Wrinkle Scale)	Adverse effects 22/182 (12%) with incobotulinumtoxin A 2/89 (2%) with placebo	Significance not reported
RCT	227 people, aged 18 to 65 years, with moderate to severe glabellar lines at maximum frown (score of 2 or above on the Facial Wrinkle Scale)	Adverse effects with botulinum toxin type A (BoNT-A) with placebo	Significance of overall analysis for treatment-related adverse effects not reported
RCT 4-armed trial	162 people, aged 18 to 65 years, with moderate to severe (grade 2 or 3) crow’s feet during maximum smile, and mild to severe (grade 1, 2, or 3) crow’s feet at rest on both sides of the face	Adverse effects with botulinum toxin type A (BoNT-A) with placebo Absolute results not reported	Analysis versus placebo not reported
RCT	158 people, aged 18 years and over, with moderate to severe glabellar lines according to investigator and self-assessment using a 4-point scale	Adverse effects probably or possibly related to treatment 23% with botulinum toxin type A (BoNT-A) 15% with placebo Absolute numbers not reported	P value not reported
RCT	142 people with moderate to severe glabellar lines (GLSS rating of 2 or 3 on a 4-point scale)	Treatment-emergent adverse events 38% with botulinum toxin type A (BoNT-A) 30% with placebo Absolute numbers not reported	Significance not reported
RCT 3-armed trial	142 Japanese people, aged 20 to 64 years, with glabellar lines of at least moderate severity at maximal contraction (score of 2 or more on a 4-point scale)	Adverse effects with botulinum toxin type A (BoNT-A) with placebo Absolute results not reported	Reported as not significantly different between groups
RCT	139 people, aged 25 to 60 years, with mild or moderate glabellar lines at rest or severe glabellar lines at full frown (measured on a 4-point scale where 0 = none and 3 = severe)	Adverse effects 38% with botulinum toxin type B (BTX-B) 33% with placebo Absolute numbers not reported	Significance not reported
RCT	40 women, aged 18 to 65 years, with moderate or severe glabellar lines, forehead lines, and crow’s feet (measured on a 4-point scale where 0 = none to 3 = severe)	Adverse effects with botulinum toxin type A (BoNT-A) with placebo Absolute results not reported
RCT	70 women, aged 30 to 55 years, with moderate or severe glabellar lines at maximum contraction (measured on a 4-point scale where 0 = none to 3 = severe)	Adverse effects with botulinum toxin type A (BOTOX) with placebo
RCT 4-armed trial	373 people with moderate or severe vertical glabellar lines at maximum frown	Adverse effects with botulinum toxin type A (Reloxin) with placebo
RCT	109 people with moderate or severe vertical or diagonal glabellar wrinkles at maximum frown (score of 2 or 3 on a standardised 4-point clinical scale ranging from 0 = none to 3 = severe); and mild, moderate, or severe vertical or diagonal glabellar wrinkles at rest (score of 1, 2, or 3)	Adverse effects (causal relationship could not be excluded) with botulinum toxin A (Dysport; 3 injection sites used in 1 session) with placebo
RCT	111 people with moderate or severe vertical or diagonal glabellar wrinkles at maximum frown (score of 2 or 3 on a standardised 4-point clinical scale ranging from 0 = none to 3 = severe); and mild, moderate, or severe vertical or diagonal glabellar wrinkles at rest (score of 1, 2, or 3)	Adverse effects (causal relationship could not be excluded) with botulinum toxin A (Dysport, 5 injection sites used in 1 session) with placebo
RCT 5-armed trial	77 women, aged 18 to 65 years, with clinically diagnosed moderate-to-severe glabellar lines at maximum frown (score of 2 or 3 on the Facial Wrinkle Scale)	Adverse effects with botulinum toxin type A with placebo
RCT	20 women with mentalis rhytids (chin wrinkles) of at least moderate severity (score of 2 or above on the Facial Wrinkle Scale)	Adverse effects with botulinum toxin type A with placebo
RCT 5-armed trial	162 people, aged 18 to 65 years, with bilaterally symmetrical moderate or severe crow’s feet at maximal smile (measured on a 4-point scale)	Adverse effects with botulinum toxin type A (BTX- A) with placebo Absolute results not reported	Reported as no statistically significant differences among treatment groups
RCT 4-armed trial	119 people with moderate to severe glabellar lines at maximal frown and at rest (score of 2 or more on a 4-point scale)	Adverse effects possibly or probably related to treatment with botulinum toxin type A (BTX-A) with placebo
RCT	273 people with glabellar lines of at least moderate severity at maximal frown (score of 2 or above on a 4-point scale)	Adverse effects with botulinum toxin type A with placebo	Reported that individual adverse events were at similar rates for the two groups (P >0.5)
RCT	264 people, aged 18 to 75 years, with glabellar lines of at least moderate severity at maximal frown (score of 2 or above on a 4-point scale)	Adverse effects with botulinum toxin type A (BTX-A) with placebo	Reported that there were no statistical differences in adverse effects between groups
RCT 4-armed trial	60 adults with bilateral symmetrical moderate to severe crow’s feet with maximum muscle contraction	Adverse effects with botulinum toxin type A (BTX-A) with placebo