Combining External Therapies of Traditional Chinese Medicine for Non-Alcoholic Fatty Liver Disease: A Narrative Review of Clinical Evidence, Synergistic Mechanisms and Future Directions

Abstract

Non-alcoholic fatty liver disease (NAFLD; recently re-termed metabolic dysfunction-associated steatotic liver disease, MASLD) has become the most prevalent chronic liver disease worldwide, yet pharmacologic options remain limited and lifestyle modification is difficult to sustain. External therapies of traditional Chinese medicine (TCM)-including acupuncture/electroacupuncture, moxibustion, acupoint catgut embedding, auricular acupressure, acupoint application, and cupping/bloodletting-have attracted increasing attention as safe, low-cost, and multi-targeted adjuncts for NAFLD. Although a growing number of systematic reviews and meta-analyses have individually summarized single-modality interventions, no review has yet synthesized the emerging rationale and evidence for combining these external modalities. This narrative review therefore 1) Summarizes the clinical and mechanistic evidence for each external modality, 2) Identifies the shared molecular targets that underlie their potential synergy, 3) Critically appraises the scarce but promising evidence for combined strategies, and 4) Proposes acupuncture combined with bloodletting cupping (cìluò báguàn) as a representative yet understudied combination that warrants rigorous evaluation. We conclude that, while current external-therapy evidence for NAFLD is promising, it is limited by small samples, heterogeneity, and predominantly indirect or metabolic surrogate outcomes; well-designed, adequately powered randomized controlled trials of rationally designed combination protocols are the logical next step.