Efficacy, Safety and Mechanisms of Acupuncture and Electroacupuncture for Pain: A Narrative Review

Research into the efficacy and safety of acupuncture and electroacupuncture for the relief of various types of pain, as well as the underpinning physiological mechanisms, has been ongoing since the 1950s. Recent trends have shown a significant increase in both the quantity and quality of studies, with an increasing range of pain types being supported by high and moderate certainty evidence. The primary aim of this narrative review is to provide an overview of the most robust evidence currently available to support the efficacy of acupuncture for inflammatory, neuropathic, and visceral pain, as well as pain in different clinical contexts. This evidence synthesis brings together the results of systematic reviews, meta-analyses, umbrella or overview reviews, and evidence maps. The secondary aim of this review is to explore animal and human studies on the mechanisms of acupuncture and electroacupuncture in pain relief. Despite potential underestimation of effect sizes in existing studies, high to moderate certainty evidence supports the efficacy of acupuncture and electroacupuncture in managing a broad range of acute and chronic pain conditions, with a consistently favourable safety profile. These interventions have been shown to induce lasting neuromodulatory effects in both central and peripheral nervous systems, partly through the reversal of maladaptive neuroplasticity and sustained modulation of central and peripheral nervous system activity. Emerging evidence highlights the analgesic, antihyperalgesic, and anti-inflammatory properties of acupuncture and electroacupuncture, underscoring their potential in contemporary pain management.