A Cochrane review ¹ included 12 RCTs with a total of at least 2349 subjects with frequent episodic or chronic tension-type headaches. The number of acupuncture sessions varied between 6 and 15, observation periods varied between 8 and 64 weeks.

• Acupuncture vs. routine care or treatment of acute headaches only: Two trials (n=1265 and 207): the proportion of participants experiencing at least 50% reduction of headache frequency was much higher in groups receiving acupuncture than in control groups (Trial 1: 302/629 (48%) vs. 121/636 (19%); RR 2.5; 95%CI 2.1 to 3.0; Trial 2: 60/132 (45%) vs. 3/75 (4%); RR 11; 95% CI 3.7 to 35). Effects beyond 4 months were not investigated.
• Acupuncture vs. sham acupuncture: Five studies (n=753): Among participants receiving acupuncture, 205 of 391 (51%) had at least 50% reduction of headache frequency compared to 133 of 312 (43%) in the sham group after treatment (RR 1.3; 95% CI 1.09 to 1.5; 4 trials; moderate quality evidence). Results at 6 months were similar. Three trials reported the number of participants reporting adverse effects: 29 of 174 (17%) with acupuncture versus 12 of 103 with sham (12%; OR 1.3; 95% CI 0.60 to 2.7).
• Acupuncture vs. physiotherapy, massage or exercise: Four trials: No trial found a significant superiority of acupuncture and for some outcomes the results slightly favoured the comparison therapy.

Comment: The quality of evidence is downgraded by study quality (lack of blinding) and inconsistency (heterogeneity in patients, treatments and outcomes).