A systematic review by American authors, of 31 separate studies, has found that the majority of trials comparing real with sham acupuncture as a control, suggest true acupuncture is significantly more effective, measured at both early and late follow-up. The combined data showed acupuncture to be superior to medication for headache intensity, frequency, physical function and overall treatment response rate.
(Acupuncture for the Management of Chronic Headache: A Systematic Review. Anesth & Analgesia Journal 2008 Dec).