Sham acupuncture is one of these three things: 1) acupuncture for an unrelated condition, 2) needle insertion at nonacupoint locations, or 3) noninsertive simulated acupuncture. It is used in research studies to provide a "placebo" for the basis for comparison with acupuncture treatments. It has some limitations however because any kind of needling (as is options 1 and 2) may have a therapeutic effect and therefor not act as a placebo.