Acupuncture, as we have mentioned so many times, is a theatrical placebo. But what theatrical performance? I tend towards tragedy, mostly Macbeth

It is a tale

Told by an acupuncturist, full of sound and fury,

Signifying nothing.

But perhaps I should consider Peter Pan as a more apt metaphor.

Remember when Tinker Bell had chronic wing pain and was getting acupuncture and it didn't appear to be effective? And Peter turns to the audience

"Do you believe in acupuncture? … If you believe," Peter shouted, "clap your hands; don't let Tink hurt."

And Tinks pain went away for a while? I do.

There is Tinker Bell effect, where

things that are thought to exist only because people believe in them.

And that describes the effect of acupuncture perfectly. There are multiple studies that have demonstrated that patients who believe in the efficacy of acupuncture are those most likely to have an effect and the stronger the belief, the stronger the effect. And that placebo effect is significant:

When compared to waitlist, standard care, or no treatment, the effect size of acupuncture is moderate, around 0.50, meaning that a large part of the acupuncture effect is due to placebo elements.

There is now another study to show the theater that is acupuncture is Peter Pan: Response to placebo acupuncture in insomnia: a secondary analysis of three randomized controlled trials.

The study

conducted a post-hoc analysis of three randomized, double- blind, placebo-controlled trials of acupuncture for primary insomnia and residual insomnia in depressed patients. The aim of the exploratory analysis is to determine patient characteristics that are predictive of a response to noninvasive placebo acupuncture for insomnia.

And it was the belief in acupuncture that was important in responding to placebo acupuncture:

higher expectation toward acupuncture were associated with greater placebo response.

Belief is why it doesn't matter where the needles are placed, it the needles are placebo, if toothpicks are used, it acupuncture is mimed or if acupuncture is done on a rubber hand. The effects are the same as long as you believe you are getting acupuncture and you believe it will work.

It is also why any acupuncture study is a waste of time if it does not include a fake placebo intervention, reporting if blinding was successful and reporting of the belief of the patients in the intervention.  

Otherwise you will not know why Tink got better.