In a study of adults who get chronic migraine headaches, injections cut down the total number of days they had them or even other types of headaches. They also had more "crystal-clear" -pain-free - days each month, and they reported fewer days off work.
In another study, nearly half the people who took two rounds of injections reported that the number of days they had a headache each month was cut in half. After five rounds of treatment, that increased to 70% of the people.
Treatment works for migraine headaches because it blocks chemicals called neurotransmitters that carry pain signals from your brain. Shots are like a roadblock in that pathway. It stops the chemicals before they get to the nerve endings around your head and neck.