The American Academy of Neurology now recommends injections of botulinum toxin (Botox) to treat chronic migraines, based on new studies showing a small 15% reduction in migraine frequency. Specifically, the AAN endorses injections of onabotulinumtoxin A. This recommendation comes six years after the FDA approved Botox for migraines, when the AAN previously said evidence was insufficient. Botox is a purified toxin that reduces muscle contractions and pain when used in small amounts.