A systemic review suggests that a course of at least six acupuncture treatments can be a valuable option for people with frequent tension-type headache. The international team included 12 trials with 2349 adults. The findings were that acupuncture, when added to pain-killers on headache onset resulted in a reduction of headache frequency of 50% or more for 48% of participants, compared with 17% of those who were given pain-killers only. When compared with sham treatment, headache frequency halved in 52% of participants receiving true acupuncture, compared with 43% of participants receiving sham. One large, high quality trial with about 400 participants showed that the effect of true acupuncture was still present six months post treatment.