The State of 21^st Century Acupuncture in the U.S. (Pt. 4)

Editor’s Note: Part 1 of this six part series appeared in the September 2025 issue; part 2 in the October issue; and part 3 in the November issue.

Acupuncture continues to occupy a unique place in healthcare: an ancient therapy with a rapidly expanding scientific basis. In the U.S., acupuncture is increasingly integrated into hospitals, VA centers, oncology clinics, and rehabilitation facilities, yet barriers remain – particularly in reimbursement and recognition by biomedical colleagues. One way forward is to highlight the expanding body of evidence on how acupuncture works. In this segment of the series, we summarize the research around the utility of acupuncture in the treatment of pain.

Why Care About Research Evidence of AHM?

Our Acupuncture and Herbal Medicine (AHM) profession is facing many challenges, which greatly impact the livelihood and sustainability of AHM as a viable stand-alone profession, and threaten public access to AHM care. It is critical that we as clinicians effectively communicate the potential impact of integrating acupuncture and allied therapies to improve clinical outcomes, reduce costs, and optimize whole-person care.

All of these goals are supported by a substantial body of research and clinical evidence on the mechanisms, clinical and cost-effectiveness of acupuncture. Although published in highly regarded journals, the medical establishment, insurance industry and the public at large are still largely unaware of these findings.

Recognizing the research evidence does not detract from acknowledging the wisdom of the tradition on which practice is based, or from the authenticity of traditional-based practice. As acupuncturists, we can play an important role in disseminating and explaining this research, and contributing to the evidence base on which research is ultimately based.

Local and Peripheral Mechanisms of Action

Needle insertion and manipulation generate immediate tissue-level effects. Connective tissue appears to play a central role: fibroblasts respond to mechanical signaling, altering gene transcription and cell morphology. These changes create biochemical cascades that shift the inflammatory milieu and modify local blood flow.

From a clinical standpoint, this means that needling into fascia or periarticular tissue can directly influence inflammation and mobility. When explaining this to colleagues, we can describe acupuncture as a method of engaging connective-tissue mechanotransduction – a concept that resonates with both orthopedists and physical therapists.

Peripheral nerve endings are also directly modulated. Acupuncture alters neurotransmitter release at the site of stimulation, changing excitability thresholds of sensory neurons. This helps explain why patients often describe an immediate decrease in sharp or burning pain following needling, and why distal point strategies can influence pain patterns far from the site of insertion.

Neuroendocrine and Central Nervous System Pathways

Perhaps the most widely recognized mechanism is acupuncture’s influence on endogenous opioids. ß-endorphins, enkephalins and dynorphins have been repeatedly shown to increase in plasma and cerebrospinal fluid following needling. These changes are not abstract – they directly correlate with both rapid-onset and sustained analgesic effects observed clinically.

Framing acupuncture in these terms allows acupuncturists to connect with pain specialists who are increasingly cautious about opioid prescribing and are searching for non-pharmacologic analgesic strategies.

Functional neuroimaging adds another layer. More than 100 fMRI studies now document that “real” (verum) acupuncture differs meaningfully from sham. While both activate the somatosensory cortex, authentic needling consistently deactivates affective and limbic brain regions such as the amygdala.

This is clinically significant: Patients with chronic pain rarely present with pain alone; depression, anxiety and catastrophizing are part of the symptom complex. Acupuncture’s dual action on sensory and affective circuits provides a language we can use when educating behavioral health teams, demonstrating how one intervention can address both pain and mood dysregulation.

Autonomic Regulation

Auricular acupuncture has been particularly well-studied for its effects on the autonomic nervous system. Stimulation of auricular points engages vagal pathways with downstream effects on cardiovascular, respiratory and gastrointestinal regulation. This helps explain why patients with irritable bowel, palpitations or stress-related dyspnea often improve with auricular protocols.

Clinically, it underscores the value of integrating auricular treatments in settings like cardiology and gastroenterology, where autonomic imbalance is increasingly recognized as a contributor to disease.

Pain Modulation: Clinical Implications

Acupuncture modulates pain through multiple, layered mechanisms. Conditioned pain modulation (CPM) and diffuse noxious inhibitory controls (DNIC) provide a physiological framework for understanding why a small noxious stimulus (the needle) can dampen pain perception globally. Deeper needling into fascia or muscle engages different neural circuits than superficial cutaneous stimulation, yet both approaches yield therapeutic effects.

For clinicians, this means both traditional depth-based techniques and more minimal styles have scientific justification. It also offers language for interdisciplinary conversations: Acupuncture taps into the same descending inhibitory pathways that pain medicine colleagues discuss when prescribing duloxetine or other central-acting drugs.

Needle retention appears to enhance analgesic outcomes compared to quick in-and-out styles. Furthermore, evidence suggests combining acupuncture with low-dose pharmacologic therapy can be synergistic – achieving greater pain control while reducing medication burden. This is an argument acupuncturists can use with prescribing physicians who are seeking multimodal strategies to lower opioid dosages without sacrificing analgesia.

Mapping Acupoints and Channels

Modern research has identified physiological correlates for acupoints and channels. Connective-tissue planes often align with classical meridians, while many acupoints overlap with myofascial trigger points and zones of referred pain. Neuroimaging further shows that distal point stimulation produces consistent brain activation patterns, validating traditional practice of treating symptoms at a distance.

Clinically, this reinforces confidence in our traditional maps while providing a biomedical framework to explain distal needling strategies to colleagues.

Clinical Effectiveness Evidence

Large trials and meta-analyses provide robust support for acupuncture in chronic musculoskeletal pain, headache disorders and osteoarthritis. The Acupuncture Trialists’ Collaboration analyzed individual patient data in multiple studies and demonstrated not only statistically significant, but also clinically meaningful improvements, with benefits persisting for months after treatment.

These findings are critical in healthcare system conversations. Acupuncture is not just a placebo or short-term intervention, but a durable therapy that can reduce healthcare utilization over time.

Beyond pain, growing evidence supports acupuncture for insomnia, women’s health, cancer-related symptoms, and neurological conditions such as post-stroke recovery. While more research is needed, these data give acupuncturists the confidence to engage oncology, neurology and primary care colleagues in dialogue about integrative referrals.

Communicating Science in Clinical Practice

For acupuncturists, understanding these mechanisms is more than academic. It allows us to:

• Educate patients in language that enhances trust. (“Your body is releasing its own pain-relieving chemicals” resonates with those wary of pharmaceuticals.)
• Build credibility with colleagues by aligning our explanations with established biomedical concepts like descending inhibitory pathways, mechanotransduction, and limbic regulation.
• Advocate within systems by demonstrating that acupuncture aligns with healthcare priorities: opioid reduction, chronic disease management, and patient-centered, low-risk care.

Conclusion

The science behind acupuncture is increasingly clear and increasingly useful. From connective-tissue remodeling to opioid release, and from limbic deactivation to autonomic regulation, acupuncture demonstrates multi-layered mechanisms that map directly to clinical outcomes.

For acupuncturists, fluency in this science strengthens our practices, enhances our ability to educate patients and colleagues, and supports integration into healthcare systems. By weaving this evidence into our daily clinical language and encouraging student education in research, we advance not only our profession, but also the broader mission of making effective, patient-centered care more widely accessible.

For this segment in particular, we respectfully encourage you to read the original, open-access paper, “The State of 21^st Century Acupuncture in the United States,”1 to glean a more thorough understanding of the mechanisms of action contributing to our current scientific understanding of how acupuncture works physiologically and anatomically.

Next Segment

In part 5 [January 2026 issue], we will discuss acupuncture education within our profession and within the scope of practice for other professionals using acupuncture as a part of their clinical practices.

Reference

1. Smith CL, Reddy B, Wolf CM, et al. The state of 21^st century acupuncture in the United States. J Pain Res, 2024;17:3329-3354. https://doi.org/10.2147/JPR.S469491.