The US Food and Drug Administration (FDA), in 2009, demanded a black warning box on the Botox (black box warning) packages. Later, the warning box also appeared on Dysport. Note that Dysport and Azzalure are the same toxin under two different names, but the toxin is marketed as Dysport in the USA! A black Box Warning is the most stringent form of warning that the United States has (for drugs) because there may be a life-threatening effect of using the drug.
In Europe, botulinum toxin products are NOT equipped with a black box warning – it is only in the US that one has that system!
Here is the leaflet for Botox with the black warning box:
Here is the leaflet for Dysport with the black warning box:
A 2009 article in which the FDA required the warning to come on:
Also, see this April 2008 news release, where they talk about the FDA’s requirement for a new warning on the Botox products. Botox was used at the time “off-label” for children with spastic paralysis and several botulism and deaths had been seen.