Acupuncture - real or sham - is as good as medication for preventing migraine, a study has suggested.
Migraines affect women more often than men
German researchers treated almost 900 patients with either standard drugs, traditional Chinese acupuncture or "fake" acupuncture.
Virtually the same proportion of people in each group found the number of days affected by migraine was halved.
The UK's Migraine Association said the Lancet Neurology study showed there was no "one-size-fits-all" treatment.
Migraine affects up to 15% of the UK population - around two thirds of sufferers are women.
An attack can last up to 72 hours, and sufferers experience an average of 13 attacks a year.
The results come from acupuncture trials in Germany, where the treatment is commonly used to treat migraine.
The people in the study were given two sessions of either traditional Chinese acupuncture or a "sham" version - where needles were put into areas of the skin not used in traditional practice.
A third group was given standard prophylactic treatment of either beta blockers, calcium channel blockers or antiepileptic drugs.
They were treated over six weeks.
The researchers then returned to the patients between 23 and 26 weeks later and checked on whether they had been "migraine free" for 50% of days.
It was found 47% of those receiving traditional acupuncture, 39% of those given sham acupuncture and 40% of those in the drug treatment group had been migraine-free for at least 50% of the time.
Writing in Lancet Neurology, the researchers led by Dr Hans Christoph Diener of the University of Duisberg-Essen, said the results were surprising and the mechanisms unknown.
They were therefore difficult to explain, he added.
He said: "Ultimately, one could argue that the efficacy of a treatment, especially a treatment with almost no adverse events of contra-indications, is more important than the knowledge of the mechanism of action of this particular therapy.
"The decision whether acupuncture should be used in migraine prevention remains with the treating physician."
Ann Turner, director of the UK Migraine Action Association, said: "This is very interesting research.
"Migraine is such an individual and complex condition that not one treatment will work for everyone."