ResearchBlogging.orgA new study which randomized 638 adults to either standard acupuncture, individualized acupuncture, placebo acupuncture using tooth picks that did not penetrate the skin, and standard therapy found exactly what previous evidence has also suggested – it does not seem to matter where you stick the needles or even if you stick the needles through the skin. The only reasonable scientific conclusion to draw from this is that acupuncture does not work.

But let me back up a minute. Imagine if we were evaluating the efficacy of a new pain drug. This drug, when tested in open trials (no blinding or control) has an effect on reducing pain – it is superior to no treatment. When compared to a placebo, however, the drug is no more effective than the placebo, although both are more effective than no treatment.

Now imagine that the pharmaceutical company who manufactures this drug sends out a press release declaring that their drug is effective for pain, but that their research shows that a placebo of their drug is also effective (FDA applications are pending). Therefore more research is needed to determine how their drug works.  Would you buy it?

That is the exact situation we are facing with acupuncture research.

Acupuncture is the traditional Chinese medicine practice of placing thin needles to a specific depth through the skin in specific acupuncture points in order to treat illness and relieve symptoms. Claims for acupuncture, including the number and location of acupuncture points, have changed greatly over the centuries, but there is no scientific evidence base for any of these claims. Acupuncture is philosophy-based medicine, not science-based medicine. The presumed mechanism for acupuncture, according to TCM, is that the needles unblock the flow of chi (life energy) through the body. Acupuncture points are supposed to corresponds to the pathways through which chi flow, correlating to specific organs or functions in the body.

Modern proponents of acupuncture come in two basic flavors – those who promote so-called medical acupuncture, and those who restrict their claims to symptomatic relief of pain, nausea, and other symptoms. Medical acupuncture is the claim that acupuncture can actually treat real medical diseases, like cancer. It is dependent entirely on the TCM philosophy of acupuncture, including the flow of chi. Medical acupuncture is pure pseudoscience without any basis in science or evidence and does not require further consideration.

Some proponents of symptomatic acupuncture have divorced their claims from the original philosophy of acupuncture, claiming that the needling works through more prosaic mechanisms, such as the release of pain-relieving endorphins or through nerve stimulation. While these explanations are plausible, they are post-hoc speculations and have not been demonstrated to occur to a clinically relevant degree.

But before we speculate about possible mechanism, we need to establish that acupuncture has an effect – that it works for some specific indication. This has not been established, despite rather robust clinical research efforts. If there were not a cultural inertia to the notion of acupuncture the existing research would have been sufficient to abandon this modality as a dead end.

To understand the clinical research into acupuncture we need to understand how clinical scientific studies work. Typically they are designed to isolate specific variables to measure the effect, if any, of those specific variable. That is the purpose of using controls – comparing an active treatment to an inactive treatment or some other intervention. Subjects are randomized to control or treatment so that other variables will, on average, cancel each other out. Larger numbers are required for randomization to work, so larger trials are better. And subjects and evaluators are blinded to treatment so that psychological biases will be factored out.

A well-designed trial, therefore, isolates the specific treatment variable to see what effect it has.

There are two treatment variables when it comes to acupuncture. (Actually, there can be more if we include other treatments that use acupuncture, such as giving electrical stimulation through acupuncture needles – but those variables should be considered separately and they are not acupuncture itself.) The two variables specific to acupuncture are sticking needles through the skin, and the locations on the body where the needles are placed.

Here is the key to understanding acupuncture research – when these two variables are properly isolated the evidence shows that there is no measurable effect from either.  It does not matter where you stick the needles, or even if you stick them through the skin. Since these two variables are specific to acupuncture it is safe to conclude that acupuncture does not work.

This latest study, one of the largest to date, supports this conclusion. The three acupuncture arms – placing needles in a standard pattern, placing needles in an individualized pattern according to acupuncture philosophy, and touching the skin with tooth picks without penetrating the skin – showed almost exactly the same degree of symptom relief both short and long term. However, all three treatments were more effective than standard therapy. The authors conclude:

Although acupuncture was found effective for chronic low back pain, tailoring needling sites to each patient and penetration of the skin appear to be unimportant in eliciting therapeutic benefits. These findings raise questions about acupuncture’s purported mechanisms of action. It remains unclear whether acupuncture or our simulated method of acupuncture provide physiologically important stimulation or represent placebo or nonspecific effects.

The first sentence is misleading, that acupuncture was found to be effective. This is based entirely on the fact that the three acupuncture arms showed more effect than the standard treatment arm. However, this was not a blinded comparison, and did not control for al the nonspecific aspects of acupuncture treatment.

The second sentence is correct but understated. This study (and others with similar results) does not just call into question the purported mechanisms of action of acupuncture – it blows them out of the water.

The final sentence is the meat of the conclusion, but again is trying to tip toe over the obvious scientific conclusion. The authors recognize that the results of their study are consistent with placebo or nonspecific effects, without the need to invoke any specific effects from acupuncture itself. But I would say that this study, combined with other studies, does not leave the question “unclear” – it makes is very clear that there are no specific effects from acupuncture, and any effects are either due to placebo effects or are a response to the therapeutic ritual surrounding the delivery of acupuncture.

These nonspecific effects may derive from the attention of the acupuncturist, the relaxing atmosphere in which the treatment is given, and the expectations derived from introducing a novel modality into treatment. These are variables known to have a symptomatic effect. Therefore if you give treatment X plus these nonspecific effects you will measure a symptomatic benefit. Treatment X can only be said to work if it provides symptomatic benefit in excess of these other variables – which acupuncture does not.

And yet the news reports of this study almost invariably declare that “Tooth pick acupuncture works” or that “Acupuncture, real or fake, helps aching back.”  They are all buying the deceptive press release. This study was not designed and is not capable of showing that “fake acupuncture works” any more than a negative drug trial shows that “sugar pills relieve pain.” This is because, as the authors admit, you cannot separate out the nonspecific and placebo effects from the acupuncture treatment.

The spin that acupuncture proponents are placing on this type of evidence turns scientific logic onto its head. In the scientific literature the authors need to be more circumspect, probably to get past peer-review. But then to the lay press the spin begins. Study author, Dr. Daniel Cherkin, is quoted as saying:

“We found that simulated acupuncture, without penetrating the skin, produced as much benefit as needle acupuncture – and that raises some new questions about how acupuncture works.”

This is wrong – these results call into question if acupuncture works.


Once again we see that the best acupuncture clinical trials show that it does not matter where or if you place the needles. Since these are the two interventions specific to acpuncture, we can conclude (confidently, at this point) that acupuncture does not work and that any perceived benefit from acupucture is due to placebo or nonspecific effects.

The acupuncture industry needs to be called on their continued promotion of a medical modality which has already been shown to be ineffective by clinical research. The mainstream media needs to be criticized for uncritically accepting the propaganda of the acupuncture industry.


See also: Acupuncture and Back Pain — Part II.

Posted by Steven Novella

Founder and currently Executive Editor of Science-Based Medicine Steven Novella, MD is an academic clinical neurologist at the Yale University School of Medicine. He is also the host and producer of the popular weekly science podcast, The Skeptics’ Guide to the Universe, and the author of the NeuroLogicaBlog, a daily blog that covers news and issues in neuroscience, but also general science, scientific skepticism, philosophy of science, critical thinking, and the intersection of science with the media and society. Dr. Novella also has produced two courses with The Great Courses, and published a book on critical thinking - also called The Skeptics Guide to the Universe.