Can acupuncture influence the autonomic nervous system?
Some people notice they feel calmer after acupuncture, even when that wasn't why they came in.
Over the past decade, one of the most active areas of acupuncture research has focussed on why. That research centres on the autonomic nervous system, and it's helping researchers understand how acupuncture may influence processes such as pain regulation, sleep, digestion, inflammation, and the body's response to stress.
Understanding the autonomic nervous system
The autonomic nervous system is the part of your nervous system that regulates many of the functions you don't consciously think about. It helps control your heart rate, blood pressure, breathing, digestion, immune function, inflammation, body temperature, and sleep. It also plays an important role in how your body responds to stress and how it recovers afterwards.
You may have heard the autonomic nervous system described as the balance between the sympathetic ("fight or flight") and parasympathetic ("rest and digest") systems. While this is a useful starting point, the reality is more complex. The autonomic nervous system is constantly responding to information from throughout the body, making small adjustments from moment to moment to keep internal conditions within a stable range. This ability to maintain a relatively stable internal environment is known as homeostasis. One of the questions researchers are exploring is whether acupuncture can influence this regulatory system.
What does the research show?
Research over the past two decades has approached this question from several different directions. Some studies have measured changes in heart rate variability, others have examined brain activity using functional MRI, while others have investigated inflammatory pathways, vagal signalling, or changes in clinical symptoms. No single study provides a complete explanation. Instead, different lines of evidence are gradually converging on the idea that acupuncture interacts with systems involved in autonomic regulation.
What that doesn't mean is that acupuncture simply "switches on the parasympathetic nervous system." The autonomic nervous system is far more complex than an on-off switch. It consists of interconnected pathways linking the brain, spinal cord, peripheral nerves, and internal organs, all working together to regulate the body's internal environment. Current research suggests acupuncture may influence these regulatory networks rather than a single pathway in isolation. A growing body of literature now proposes that autonomic regulation may represent one of the major mechanisms through which acupuncture exerts some of its clinical effects.
Heart rate variability: measuring regulation
One way researchers study the autonomic nervous system is by measuring heart rate variability (HRV). Despite the name, heart rate variability isn't a sign that your heart is beating irregularly. Rather, it describes the tiny differences in time between individual heartbeats. A healthy autonomic nervous system is constantly making small adjustments to these intervals in response to breathing, posture, activity, emotion, and countless other internal and external signals. Higher heart rate variability is generally considered a marker of greater autonomic flexibility. It reflects the body's ability to adapt to changing demands.
Several studies have shown that acupuncture can influence HRV immediately following treatment, suggesting measurable changes in autonomic regulation rather than simply subjective feelings of relaxation. This doesn't prove acupuncture improves health through HRV alone. But it provides objective physiological evidence that something measurable is occurring.
The brain appears to be involved too
Researchers have also used functional MRI to investigate how the brain responds to acupuncture. Rather than finding changes in a single area, studies suggest acupuncture influences several interconnected regions involved in pain, emotion, autonomic regulation, and higher cognitive function. These effects have been observed across a range of conditions, from chronic pain to sleep disturbance, though the specific regions involved vary between studies.
This doesn't tell us that acupuncture will produce these changes in everyone. What it does show is that acupuncture-related stimulation appears capable of influencing brain networks involved in regulating behaviour, emotion, and autonomic function.
The vagus nerve has attracted particular attention
One of the areas that has received considerable attention in recent years is the vagus nerve. The vagus nerve is one of the body's major communication pathways between the brain and internal organs. It helps regulate heart function, digestion, inflammation, immune activity, and many aspects of recovery, making it an important part of the autonomic nervous system.
Researchers have become increasingly interested in the vagus nerve because it offers one possible explanation for how acupuncture, applied at specific points on the skin, might influence physiological processes elsewhere in the body. Much of this evidence comes from a mix of animal and human research. Animal studies can identify specific neural pathways, while human studies capture changes in physiology, brain activity, inflammatory markers, and clinical symptoms following treatment.
So why do some people feel calmer?
This is where the research becomes clinically meaningful. If acupuncture influences systems involved in autonomic regulation, then feeling calmer after treatment may be one of several physiological responses to those regulatory shifts, rather than simply the result of having had time to rest. Not everyone experiences this. Some people notice a profound sense of calm, others simply sleep better that night. Some notice improvements in digestion, muscle tension, or their ability to concentrate, and some notice very little immediately after treatment at all.
None of these experiences are "more correct" than another. Like most healthcare interventions, individual responses vary.
What this means in clinical practice
One of the reasons I ask how you've felt in the days following treatment, not just whether your original symptom has changed, is that those observations often provide useful clinical information.
Has your sleep changed? Has your digestion felt different? Have you felt more settled? Sometimes those changes help us understand how your body is responding before the primary symptom has even started to improve.
Where the research is heading
Like most areas of medicine, our understanding of acupuncture continues to evolve. One of the clearest themes emerging from current literature is a growing interest in how acupuncture may influence the body's systems of regulation. The autonomic nervous system appears to be one important piece of that puzzle. It may not provide the whole explanation, but it's helping researchers understand how acupuncture could produce effects across multiple body systems at once.
Research referenced in this article
This article draws on a selection of peer-reviewed research. For readers interested in exploring the evidence further, the studies referenced include:
Hamvas, S. et al. (2023). Acupuncture increases parasympathetic tone, modulating HRV − Systematic review and meta-analysis. Complementary Therapies in Medicine, 72, 102905, https://doi.org/10.1016/j.ctim.2022.102905.
Ma, Y. et al. (2025) Clinical efficacy and safety of acupuncture in modulating autonomic nervous function: a meta-analysis of randomized controlled trials. Frontiers in Neuroscience. https://doi.org/10.3389/fnins.2025.1694110
Li, L. et al. (2025). Regulation of autonomic nervous system by acupuncture: A heart rate variability study on physical stress. Frontiers in Human Neuroscience. 19, 1676863. https://doi.org/10.3389/fnhum.2025.1676863
Liu, S. et al. (2021). A neuroanatomical basis for electroacupuncture to drive the vagal–adrenal axis. Nature. 598, 641–645. https://doi.org/10.1038/s41586-021-04001-4
Li, QQ. et al. (2013). Acupuncture effect and central autonomic regulation.Evidence-Based Complementary and Alternative Medicine. 267959. https://doi.org/10.1155/2013/267959
Li, YW. et al. (2022). The autonomic nervous system: A potential link to the efficacy of acupuncture. Frontiers in Neuroscience, 16, 1038945. https://doi.org/10.3389/fnins.2022.1038945
Oh, J-E. & Kim, S-N. (2022). Anti-Inflammatory effects of acupuncture at ST36 point: A literature review in animal studies. Frontiers in Immunology. https://doi.org/10.3389/fimmu.2021.813748
Lim, HD. et al. (2016). Anti-inflammatory effects of acupuncture stimulation via the vagus nerve. PLOS ONE, 11(3), e0151882. https://doi.org/10.1371/journal.pone.0151882
Torres-Rosas, R. et al. (2014). Dopamine mediates vagal modulation of the immune system by electroacupuncture. Nature Medicine. 20(3), 291–295. https://doi.org/10.1038/nm.3479
Last reviewed: July 2026
This article reflects the evidence available at the time of publication and will be updated as new research emerges.
