The most deadly toxin is botulinum toxin, a type of bacteria that causes botulism, a condition that can result in paralysis of the central nervous system and lead to respiratory failure. It is thought to be more than 10 million times more lethal than cyanide. Botulinum toxin can enter the body through open wounds or by consuming contaminated food. Purified versions of botulinum toxin, including the well-known brand Botox®, are approved for cosmetic usage and are often injected into people's faces to smooth wrinkles. This works because traces of the toxin cause slight, temporary paralysis of the facial muscles that cause wrinkles.
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