The large multi-centre German Acupuncture Trials (GERAC), suggests that both real and sham acupuncture are much more effective against chronic low back pain than conventional therapy. The patient- and observer-blinded randomised controlled trial involved 340 outpatient practices, including 1162 patients aged 18-86 years (average 50) with a history of chronic low back pain lasting an average of eight years. This represents the largest experimental trial so far of acupuncture for back pain. Participants underwent ten 30-minute sessions (two per week), of verum acupuncture (according to TCM principles), sham acupuncture (superficial needling at nonacupuncture points on the lower back), or conventional therapy (a combination of drugs, physical therapy and exercise). The primary outcome measure was response after six months, defined as a 33% improvement on pain scores or a 12% improvement in functional ability. At six months, the response rate was 47.6% in the verum acupuncture group, 44.2% in the sham acupuncture group, and 27.4% in the conventional therapy group. The difference between response to real vs sham acupuncture was not significant, but both were almost twice as effective as conventional therapy.

German Acupuncture Trials (GERAC) for chronic low back pain: randomized, multicenter, blinded, parallel-group trial with 3 groups. Arch Intern Med. 2007 Sep 24;167(17):1892-8.