Botulinum toxin is a potent neurotoxin produced by the bacterium Clostridium botulinum. It blocks nerve signals to muscles, leading to temporary paralysis. This toxin is responsible for the serious illness known as botulism, which can occur from contaminated food or wounds. In controlled doses, botulinum toxin is used in medical and cosmetic procedures. It is commonly known for its application in reducing wrinkles and treating conditions like chronic migraines and muscle spasms. The effects of the toxin can last for several months, making it a popular choice for both therapeutic and aesthetic purposes.