The American Academy of Neurology (AAN) is backing the use of a popular muscle relaxant to treat migraine headaches. In its updated guidelines, published online April 18, 2016, by Neurology, the AAN recommends injections of botulinum toxin (Botox) as a way to help reduce the frequency of chronic migraines. The recommendation comes six years after the FDA gave its approval of Botox for migraines. At that time, the AAN said the evidence was insufficient. Now the AAN points to studies that support the use of a particular type of Botox—onabotulinumtoxin A—to decrease how often people get migraines, although the AAN says it's just a small reduction (15%). But for some people who get side effects from medications to treat migraine headaches, Botox injections are an alternative. Botox is a purified form of a toxin produced by bacteria. In small amounts, it is not toxic; it reduces muscle contractions and pain. The AAN also recommends Botox injections to treat certain muscle spasms. Cosmetically, Botox injections are used to reduce frown lines in the forehead.