Ivy, specifically Hedera helix (English ivy), is used to support the bronchial and respiratory systems. There is a considerable body of scientific evidence supporting its use, particularly as an expectorant in cases of productive cough associated with bronchitis. The active constituents in ivy leaf extracts, such as saponins (notably alpha-hederin), appear to have mucolytic (mucus-thinning), bronchodilatory, and anti-inflammatory properties.

Multiple clinical trials and meta-analyses indicate that standardized ivy leaf extract can reduce cough frequency and improve symptoms of acute and chronic bronchitis in both adults and children. For example, a 2015 systematic review in Phytomedicine and several randomized controlled trials have shown statistically significant improvements in cough scores and mucus clearance compared to placebo. Ivy preparations are commonly included in over-the-counter cough syrups in Europe, and their safety profile is generally favorable, with only mild gastrointestinal side effects reported in some cases.

The German Commission E and the European Medicines Agency (EMA) both recognize ivy leaf extract as a traditional herbal medicinal product for the relief of productive cough associated with cold. While the precise mechanism of action is still being explored, the available scientific data provide moderate to strong support for its use in supporting the bronchial system.