Benign side effects are very well-localized, reversible and self-limited difficulties which develop inside of a couple of days on the injection, and they sometimes vanish without any treatment. The aesthetic and functional adverse effects are linked to different muscle responses to botulinum toxin or with misplacement of botulinum toxin. https://andresiucio.wikiparticularization.com/1557982/everything_about_botulinum_toxins_exotoxins_of_clostridium_botulinum