Trademark for botulinum toxin type A, a drug produced by the bacterium Clostridium botulinum .
It contains the same toxin that causes severe food poisoning (botulism). When locally injected, Botox blocks the release of the neurotransmitter acetylcholine, interfering with the ability of the muscle to contract. It is used to treat severe muscle spasm or severe, uncontrollable sweating. Botox can also be used for cosmetic purposes to treat facial wrinkles.