Botox is a form of botulinum toxin, a neurotoxin produced by the bacteria that causes botulism. When the Botox botulinum toxin is purified and used in tiny doses in specific areas, it temporarily reduces muscle contractions for approximately 3 months.
Botox is injected around pain fibers that are involved in headaches. Botox enters the nerve endings around where it is injected and blocks the release of chemicals involved in pain transmission. This prevents activation of pain networks in the brain.