Botox is a drug made from a toxin produced by the bacterium Clostridium botulinum. It's the same toxin that causes a life-threatening type of food poisoning called botulism.
After their ingestion, botulinum neurotoxins are absorbed primarily in the duodenum and jejunum and pass into the bloodstream and travel to synapses in the nervous system. There, the neurotoxins cause flaccid paralysis by preventing the release of acetylcholine, a neurotransmitter, at neuromuscular junctions, thereby preventing motor-fiber stimulation. The flaccid paralysis progresses symmetrically downward, usually starting with the eyes and face, then moving to the throat, chest, and extremities. When the diaphragm and chest muscles become fully involved, respiration is inhibited and, unless the patient is ventilated, death from asphyxia results. Classic symptoms of botulism include nausea, vomiting, fatigue, dizziness, double vision, drooping eyelids, slurred speech, difficulty swallowing, dryness of skin, mouth, and throat, lack of fever, muscle weakness, and paralysis.
In foodborne botulism cases, symptoms usually begin anywhere between 12 and 72 hours after the ingestion of toxin-containing food. Longer incubation periods—up to 10 days—are not unknown, however. The duration of the illness is from 1 to 10 (or more) days, depending on host-resistance, the amount of toxin ingested, and other factors. Full recovery often takes from weeks to months. The mortality rate can be from 30% to 65%, with rates generally lower in European countries than in the United States.