The topic of placebo or sham acupuncture controls is a very complicated one in acupuncture research, and not one where there is universal agreement. However I’ll outline some of the key findings and things to keep in mind whenever you see a study that compares acupuncture to a placebo, sham or other type of minimal acupuncture as a control.

Researchers have been attempting to come up with an acceptable placebo control for acupuncture treatments for many years. These placebos have run the gamut from tapping a point with no needle insertion to inserting a needle in a non-acupuncture point, to a special device that gives the appearance that an acupuncture needle is inserted into the body, when really it has not penetrated the body at all. 

A placebo should be physiologically inert; such as when comparing a new medication to the placebo of a sugar pill or empty capsule. A placebo should not create any of the physiological effects of the treatment. There isn’t yet clarity on what exactly the physiological effects specific to acupuncture are, so this of course makes it difficult to create a sham acupuncture treatment which doesn’t have any of these effects. 

After much analysis, researchers have found that acupuncture placebos/sham acupuncture treatments are not physiologically inert. How do we know this? According to Langevin et al., “Sham acupuncture treatments have consistently been shown to have greater therapeutic effects than conventional placebos (2).” In addition, when comparing studies where acupuncture treatment is compared to no treatment at all or usual care, the effect size is consistently larger than studies where acupuncture treatment is compared to a “sham” acupuncture placebo. These “sham” acupuncture treatments are thought to have some degree of physiological effect in combination with some degree of placebo effect. The amount of each is impossible to know at present time, because the exact mechanisms of acupuncture are still being determined.

At the current time, researchers (including at the NIH) are prioritizing acupuncture mechanisms research as well as studies that compare acupuncture to usual care or to another modality (for example, acupuncture compared to physical therapy for lower back pain) (1).