Thread-Embedding Acupuncture: Traditional Theory, Modern Mechanisms, And Clinical Evidence

Thread-embedding acupuncture is a modified acupuncture technique in which absorbable threads are implanted into selected acupoints to provide prolonged therapeutic stimulation. Originating from Traditional Chinese Medicine (TCM), this intervention has been increasingly incorporated into integrative medical practice, particularly for chronic and recurrent conditions requiring sustained regulation. This narrative mini-review aims to synthesize current knowledge on the traditional theoretical basis, proposed biomedical mechanisms, and clinical evidence of thread-embedding acupuncture, while also addressing safety considerations and research limitations. From the perspective of TCM, thread-embedding acupuncture is grounded in meridian theory and the regulation of Qi and Blood, with continuous acupoint stimulation considered beneficial for long-term functional modulation. Contemporary biomedical interpretations suggest that its effects may involve a combination of neurophysiological modulation, localized tissue responses induced by absorbable materials, and broader neuroendocrine and immune regulatory processes. However, much of the mechanistic evidence remains indirect or preliminary, with limited studies specifically investigating this modality. Clinical evidence includes randomized controlled trials, observational studies, and systematic reviews, primarily conducted in East Asia. While many studies report improvements in pain, functional outcomes, and symptom severity, particularly in chronic musculoskeletal and certain neurological conditions, the overall strength of evidence is limited. Methodological weaknesses, including small sample sizes, heterogeneity in intervention protocols, variability in outcome measures, and risk of bias, restrict the reliability and generalizability of findings. Reported effect sizes are often modest or inconsistently quantified, and long-term outcomes remain insufficiently evaluated. Available data suggest that thread-embedding acupuncture is generally well tolerated when performed by trained practitioners, although adverse events such as localized inflammation and infection have been reported. In summary, thread-embedding acupuncture represents a promising integrative therapeutic approach; however, current evidence is insufficient to support definitive conclusions regarding its efficacy. Further high-quality, well-designed clinical trials and targeted mechanistic studies are required to clarify its therapeutic value, safety profile, and role within evidence-informed integrative medicine.