Botox cosmetic drug. Botox is a neurotoxin used for preventing wrinkles and for smoothing the skin. The toxin, Botulinum Toxin Type A, is obtained from Clostridium botulinum bacteria. Small amounts of the toxin are injected into facial muscles. This paralyses the muscles, which has the effect of smoothing wrinkles. The toxin was first identified in a case of botulism, a form of bacterial food poisoning that can lead to paralysis and death. The botox treatment uses far less toxin than the lethal dose. One treatment may last for three to four months. Side-effects may include an expressionless face.