A review of 22 trials that investigated whether acupuncture is effective for the prevention of migraine attacks. Patients who received acupuncture had fewer headaches than those given basic care. ‘True’ acupuncture and sham acupuncture seemed to be similarly effective. When acupuncture was compared to proven drug treatment, patients receiving acupuncture tended to report more improvement and fewer side effects. Overall, migraine patients benefited from acupuncture, and it was at least as effective as, or possibly more effective than, drug treatment, with fewer adverse effects.