Pelargonium, specifically Pelargonium sidoides, has been traditionally used in South African herbal medicine for respiratory ailments, and its extracts (commonly sold as “Umckaloabo”) have been investigated in several modern clinical studies for their effects on the bronchial system. Randomized controlled trials, systematic reviews, and meta-analyses have examined Pelargonium extract’s efficacy in treating acute bronchitis, sinusitis, and other respiratory tract infections. Results suggest that standardized Pelargonium extracts may reduce the duration and severity of acute bronchitis symptoms in adults and children when compared to placebo. The proposed mechanisms include antimicrobial, antiviral, and immunomodulatory effects, although the exact bioactive compounds and their actions are not fully elucidated.

Major health authorities, such as the European Medicines Agency (EMA), recognize Pelargonium sidoides extract as a traditional herbal medicinal product for the relief of symptoms of common cold and acute bronchitis, based on both its traditional use and supportive clinical evidence. However, while the evidence is promising, it is not without limitations: not all studies are of high quality, and most research is on specific standardized extracts rather than unspecified Pelargonium species or preparations. Safety is generally good, but rare allergic or gastrointestinal side effects have been reported. In summary, there is moderate scientific evidence supporting the use of certain Pelargonium extracts for bronchial support, but results should not be generalized to all Pelargonium products.