Benefits and Harms of Herbal Medicines for Preventing and Treating Acute Respiratory Infections: An Overview of Systematic Reviews.

Hundreds of herbal medicines are currently marketed for the management of acute respiratory infections (ARIs). However, there is uncertainty about their benefits and harms, and clinical guidance remains unclear. Our objective was to evaluate the benefits and harms of herbal medicines for preventing and treating ARIs using the evidence from published systematic reviews. We conducted electronic searches in MEDLINE, Embase, CINAHL, and the Cochrane Library. We also searched Google Scholar and the bibliography of relevant studies. We included reviews of herbal medicines or herbal medicine combinations for the prevention or treatment of ARIs. Our primary outcomes were infection rates, symptom resolution, symptom duration, and symptom severity. We used AMSTAR-2 criteria to assess the quality of included reviews. Two reviewers independently screened abstracts, assessed quality, and extracted the data. We included 18 reviews evaluating the effectiveness of 16 different herbal medicines. A total of 13 were rated high quality, and five were rated moderate quality. Seven reviews of ginseng, ivy leaf extract, echinacea, eucalyptus, and black elderberry showed some benefits in the management of ARIs. The evidence from the remaining 11 reviews was either insufficient or inconclusive. No serious adverse events were reported; however, adverse events were likely underreported. Herbal medicines show modest benefits for managing ARIs, but the evidence remains limited by methodological flaws in the primary studies. While some treatments appear promising, current data are insufficient for strong clinical recommendations. High-quality, large-scale RCTs are needed to confirm efficacy, assess safety, and guide clinical use.