Botox is the brand name of a neurotoxin known as botulinum toxin, which works by paralyzing or weakening muscles and nerves. The same toxin, if consumed, can cause botulism poisoning, which is dangerous and sometimes fatal because it can paralyze the respiratory system.
It was ophthalmologists who first discovered that the ability to target specific muscles or nerves for paralysis might have a place in medicine, using botulinum toxin to treat crossed eyes and excessive blinking beginning in the ’80s. In 2002, Botox became a household name when it was first approved for cosmetic use. But researchers have continued to examine what they call “therapeutic” (i.e. non-cosmetic) uses for the drug, and physicians, who are permitted in the U.S. to prescribe drugs “off-label,” or for uses other than those approved by the U.S. Food and Drug Administration, are experimenting with Botox to relieve other conditions.