Botulinum toxin is a naturally purified protein whose role is to temporarily block the release of acetylcholine, the chemical responsible for transmission between the nerve endings and muscles. This effect causes the relaxation of the overactive muscles. It is often prescribed to treat medical conditions such as chronic migraines, eyelid spasm and even excessive sweating (in the armpits, hands, feet).
Cosmetically, botulinum toxin can be used to treat facial lines, by relaxing facial muscles to smooth unwanted wrinkles and stop deeper lines from forming. It is also effective in jaw reduction.