Botulinum toxin

Botulinum toxin is a neurotoxic protein that inhibits acetylcholine release at nerve endings, leading to flaccid paralysis. It is considered the most toxic substance known by weight, with lethal doses in the nanogram range. Historically linked to foodborne botulism, it is now purified and used therapeutically to treat muscle spasms, dystonias, chronic migraines, and excessive sweating. In cosmetics, it is famous as Botox, reducing wrinkles by temporarily paralyzing facial muscles.