Dry Needling: A Scoping Review of Adverse Outcomes

Introduction:Dry needling (DN) is commonly used in physiotherapy to treat musculoskeletal pain. While some evidence suggests modest short-term relief, the overall efficacy remains inconsistent, and the safety profile is not well established. Adverse events are frequently underreported, and few reviews have systematically examined the range and quality of harm-related evidence. This scoping review aimed to identify and categorize reported adverse outcomes associated with DN and related needling therapies in adults with musculoskeletal conditions. We also evaluated how adverse events are tracked and reported, along with key methodological limitations in the literature.Materials and Methods: We conducted a comprehensive search of six databases (PubMed, MEDLINE, EMBASE, Scopus, Web of Science, and Google Scholar) for studies published between January 2000 and April 2025. Eligible studies included randomized controlled trials, observational studies, case reports, and systematic reviews reporting adverse events related to DN and intramuscular stimulation (IMS). Data were charted based on adverse event type, severity, and reporting quality. Results: Of 2,258 records screened, 26 studies met inclusion criteria. Adverse events ranged from minor issues (e.g., bruising, soreness) to serious complications including pneumothorax, deep infection, nerve injury, and spinal hematoma. Minor effects were reported in up to 50% of treatments. Underreporting was widespread, and most studies exhibited significant methodological flaws, such as small sample sizes, inadequate blinding, and publication bias.Conclusion: DN poses a nontrivial risk of harm. Rigorous safety monitoring, transparent reporting, and stronger study designs are urgently needed to guide responsible clinical use.