Botulinum toxin, or botulinum neurotoxin (commonly called botox), is a very powerful neurotoxic protein created by the bacterium Clostridium botulinum. It stops the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction.
The neurotoxin creates flaccid paralysis. The toxin causes the disease botulism. The toxin is also used widely for medical and cosmetic reasons.