How does acupuncture work?

An acupuncture needle induces an effect in the area that it is inserted but also in the rest of the body.

Local effects

  • Increased blood flow resulting in enhanced healing – caused by signalling molecules (neuropeptides) which trigger vasodilation (widening) of the blood vessels
  • Pain relief – needle insertion causes mild tissue damage and structural tissue changes which triggers cells to release a substance called adenosine which at low levels blocks transmission of pain signals
  • Reduced inflammation and enhanced functioning of the immune and nervous system – linked to the release of signalling proteins called cytokines

Segmental effects

  • Stimulation of the nerve fibres in the skin, muscle and connective tissue result in a signal being transmitted to the spinal cord. This signal triggers various processes to occur that block the transmission of pain signals from the spinal cord to the brain. This Gate Control Theory of Pain was introduced by Melzack and Wall in 1965.
  • Tissues that are far apart on the body can be innervated by the same spinal segment. This means for example that abdominal pain may be treated using certain acupuncture points on the leg (e.g. the tibialis anterior) as the nerves from both these areas converge at the same spinal segment.

Effects on the brain centres

Acupuncture stimulates release of:

  • Opioid peptides – these act on opioid receptors to reduce pain
  • Oxytocin – has pain blocking, anti-anxiety and sedative effects
  • Gonadotropin – helps regulate and reduce painful menstruation
  • β- Endorphin – reduces menopausal hot flushes

Acupuncture may also:

  • Help restore a dysfunctional Default Mode Network (the brain state at wakeful rest) – this may help patients with chronic pain
  • Deactivate the limbic system to improve the patient’s emotional component of pain

Certain acupuncture points can activate the vagus nerve which is important for:

  • Reduced inflammation
  • Improved digestion
  • Improved immune function
  • Reduced anxiety

Other effects

  • Reduction in anxiety by stimulating release of hormones and neurotransmitters such as serotonin
  • Reduction in nausea and vomiting possibly by blocking the brain’s chemoreceptor trigger zone for vomiting

For more information:

Gao P, Gao XI, Fu T, Xu D, Wen Q. Acupuncture: Emerging evidence for its use as an analgesic (Review). Exp Ther Med. 2015 May;9(5):1577-1581. doi: 10.3892/etm.2015.2348. Epub 2015 Mar 12. PMID: 26136861; PMCID: PMC4471669.

Kwokming James Cheng. Neurobiological Mechanisms of Acupuncture for Some Common Illnesses: A Clinician’s Perspective. Journal of Acupuncture and Meridian Studies, Volume 7, Issue 3, 2014, Pages 105-114, ISSN 2005-2901,
https://doi.org/10.1016/j.jams.2013.07.008.
(https://www.sciencedirect.com/science/article/pii/S200529011300174X)

Xu, G., Zhao, X., Li, Z. et al. Effects of electroacupuncture on the kisspeptin-gonadotropin-releasing hormone (GnRH) /luteinizing hormone (LH) neural circuit abnormalities and androgen receptor expression of kisspeptin/neurokinin B/dynorphin neurons in PCOS rats. J Ovarian Res 16, 15 (2023). https://doi.org/10.1186/s13048-022-01078-x

Zhang Y, Zhang H, Nierhaus T, Pach D, Witt CM, Yi M. Default Mode Network as a Neural Substrate of Acupuncture: Evidence, Challenges and Strategy. Front Neurosci. 2019 Feb 11;13:100. doi: 10.3389/fnins.2019.00100. PMID: 30804749; PMCID: PMC6378290.