Medicinal plants vs metronidazole in bacterial vaginosis: a narrative review of evidence from randomized clinical trials.

Background: Bacterial vaginosis (BV) is a common vaginal infection in women of reproductive age and is often linked to a vaginal microbiota imbalance. Conventional antibiotics such as metronidazole are effective but are associated with side effects and recurrence, prompting interest in herbal alternatives. Objectives: To compare the clinical efficacy of medicinal plants versus metronidazole in the treatment of bacterial vaginosis using evidence from randomized clinical trials. Methods: This narrative review examined randomized clinical trials evaluating herbal interventions for bacterial vaginosis. Web of Science, Scopus, PubMed, and ScienceDirect were searched for studies published up to March 2026. The included studies assessed herbal interventions administered orally or vaginally, alone or with conventional metronidazole therapy. Information on plant species, study design, participants, diagnostic criteria, interventions, results, and conclusions was extracted and synthesized narratively. Results: Twenty-four published articles were included, covering a range of medicinal plants, including Allium sativum, Myrtus communis, Quercus species, Berberis vulgaris, Zataria multiflora, Calendula officinalis, Cymbopogon olivieri, and others. Herbal therapies showed efficacy comparable to or superior to metronidazole, with fewer side effects and lower recurrence rates. Their effects are attributed to bioactive compounds, including allicin, curcumin, berberine, tannins, flavonoids, and essential oils, which exhibit antimicrobial, anti-inflammatory, and antioxidant properties. Conclusions: Medicinal plants appear to be safe and effective alternatives or adjuncts for bacterial vaginosis; however, the heterogeneity in study designs and short follow-up periods limits definitive conclusions. Further well-designed, multicenter randomized trials with standardized protocols and long-term follow-up, along with studies exploring individual plants and their mechanisms of action, are needed to confirm efficacy, safety, and reproducibility and to support evidence-based use.