Creating a study to properly measure the effectiveness of acupuncture has proven difficult because the gold standard, the double-blind random controlled study, was designed to test pharmaceuticals against a placebo/sugar pill.
There simply is no good way to "fake" an acupuncture treatment. And even if sham acupuncture could be devised it would be impossible for the person administering the treatment to be "blind" to the knowledge of whether they were giving real acupuncture or sham acupuncture.
However, the tide is turning and different ways of approaching the need to scientifically prove the effectiveness of acupuncture are being found. In a Georgetown University study, neuropeptide y (NPY) a protein associated with stress, was measured before and after acupuncture treatment. Findings concluded an immediate and long lasting reduction in the protein measured.
The study is significant because once duplicated, acupuncture will be "scientifically" proven as a treatment for stress. Since stress is a recognized precursor for so many more serious ailments there is hope that this scientific finding will open the door for a wider acceptance and use of this valuable therapy.
In the meantime, the US Military after performing it's own vigorous studies has recognized publicly the value of acupuncture and introduced the therapy into both Veteran's Hospitals and combat settings.