How does acupuncture work? A look at the theories, east and west

It probably comes as no surprise that this is one of the questions I’m asked most often in clinic. I think every acupuncturist would love to be able to offer a clear, black-and-white answer. The truth is, nobody has one.

So below is a deeper dive into the leading theories, and a reflection on why, in practice, we don’t necessarily need to understand every detail of how something works for it to be effective.

The Western point of view - challenges and research

I’ll start by saying that acupuncture is, by nature, a difficult subject to research. A typical Randomised Control Trial - considered the gold standard, as it minimises bias -works by assigning participants at random to either a treatment group or a control group, usually receiving a placebo or standard care. Randomisation, and often blinding, helps reduce bias and keeps the groups comparable. Researchers then measure outcomes and use statistical analysis to work out whether any differences are genuinely down to the treatment, rather than chance.

Acupuncture doesn’t sit easily within this model, for a few reasons.

Blinding is difficult.

In drug trials, you can give a pill or a placebo pill that looks identical. With acupuncture, it’s much harder to create a convincing "sham" procedure. Even when non-penetrating needles or incorrect points are used, participants may still feel something and practitioners almost always know whether they’re delivering the real treatment or not.

Placebo controls are complicated.

Inserting needles almost anywhere on the body can produce a physiological effect, so a "fake" version isn’t necessarily inert. This makes a true control condition genuinely hard to design. I’ll come back to the so-called placebo effect a little further down -it tends to carry a rather negative connotation, but if something produces a placebo effect, that effect can still be a powerful one.

Acupuncture is highly individualised.

Practitioners typically tailor point selection to the person in front of them, based on their unique health history and symptoms, whereas RCTs favour standardised protocols to keep things consistent. Standardising treatment for the sake of a trial can therefore strip away part of how acupuncture is actually practised.

Outcomes like pain are subjective.

Outcomes can be more susceptible to expectation and placebo effects than something you can simply measure on a scan.

With all that in mind, the most reliable research we do have suggests acupuncture works by:

• Stimulating nerve fibres
• Triggering the release of endorphins and other neurotransmitters
• Modulating pain pathways in the brain and spinal cord
• Influencing local blood flow and inflammatory processes

There’s also some genuinely fascinating research emerging around the interstitium - a relatively recent anatomical discovery describing a vast, interconnected network of fluid-filled spaces running through our connective tissue. Researchers believe this network links organs, muscles, nerves, blood vessels and other tissues throughout the body, and may act as a major system for fluid transport, mechanical support and biological signalling. Source: https://www.nytimes.com/interactive/2026/05/11/magazine/interstitium-anatomy-acupuncture-medicine.html

None of this comes as a surprise to acupuncturists. Interestingly, many acupuncture points sit within the same areas of connective tissue where fluid moves through the interstitium and when researchers injected dye into acupuncture points on volunteers’ forearms, it slowly migrated up the arm along the path of a meridian. Food for thought.

The Traditional Chinese Medicine point of view - principles and foundations

Chinese medicine is at least a 2,000-year-old medicine and given the growing attention and the positive results it continues to produce, it’s clearly here to stay.

Put as simply as I can, TCM views health as the smooth, balanced flow of Qi through the body, along pathways known as channels or meridians. Illness is thought to arise when Qi becomes blocked, deficient or in excess, and health also reflects a balance between Yin and Yang.

Acupuncture takes a holistic approach. It considers the whole person - how symptoms relate to one another, and how body and mind influence each other. Treatment is individualised, targeting each person’s unique pattern of imbalance and health history, to address the root cause of illness rather than simply covering over the symptoms.

The case for placebo

I recently read about some trials involving ketamine - the dissociative anaesthetic that also has certain hallucinogenic effects. It has a well-documented and robust antidepressant effect, but researchers believe that its placebo response plays a meaningful part in that too. https://pmc.ncbi.nlm.nih.gov/articles/PMC12547681/

Reading this made me reflect again on the placebo effect, and the slightly negative connotation it tends to carry. But here’s the thing, even if acupuncture was "just" a placebo, it would still be producing real, positive results for the person experiencing them. That’s not nothing.

And here’s something I find curious. Understandably, we often what to know exactly how something like acupuncture works, and yet most of us would happily take a paracetamol without knowing how it does its job. In fact, the precise mechanism of paracetamol still isn’t fully understood (e.g. https://pubmed.ncbi.nlm.nih.gov/21054454/). The same goes for many medications used to treat depression, bipolar disorder and diabetes - their effects are well documented, but their exact mechanisms are still only partially explained. So perhaps we don’t always need the full picture of how something works to trust that it does. Which is why I’ll always say you need to trial acupuncture to see if it’s for you - because if it is, you’ve found yourself the most intuitive, logical and effective therapy out there. But I’m biased. Try it for yourself.

If you want to dive deeper

If any of this has piqued your curiosity, here are a few books I’d recommend - a mix of gentle introductions and denser reads for those who want to go further.

• The Web That Has No Weaver by Ted Kaptchuk - the classic. If you only read one book on the theory behind Chinese medicine, I’d make it this one. It’s thorough, thoughtful, and remains one of the clearest explanations of Qi, Yin and Yang, and the patterns TCM works with.
• The Spark in the Machine by Dr Daniel Keown - written by a Western-trained doctor who also studied acupuncture, this one does a lovely job of building a bridge between the two systems, using embryology to make sense of the meridians.
• Between Heaven and Earth by Harriet Beinfield and Efrem Korngold - a warm, readable introduction to the philosophy behind Chinese medicine, with plenty of everyday context. A good starting point if the theory side feels unfamiliar.