Benefits
Expectorant support for a productive cough
European regulators accept specified ivy leaf dry and liquid extracts, under the EU category for long-standing medical use, as an expectorant for a productive (chesty) cough. The monograph says how the extract works in people is not known, and advises seeing a doctor or pharmacist if the cough lasts beyond a week.
Faster easing of short-term cough versus placebo
In two double-blind trials in about 390 adults, both tied to the maker, with a recent cough, one ivy extract lowered cough and chest symptom scores faster than placebo over a week, and more people were cough-free at two weeks. Independent reviewers rate the overall gain from ivy as minimal at best and of uncertain clinical importance.
Airway function in children already using inhaled treatment
In children with asthma, one older placebo-controlled trial found that ivy drops lowered airway resistance. In a newer placebo-controlled crossover trial in 30 children who stayed on inhaled steroids, the main lung function outcomes did not change, though some secondary readings rose. Ivy leaf does not replace prescribed asthma care; never cut back an inhaler.
Tolerability in adults and children
In placebo-controlled adult trials, side effect rates were similar to placebo. An open study of 464 children aged 2 to 12 reported no adverse drug reactions. Regulators list stomach upset and allergic reactions as known side effects and do not allow use under age 2.
Mechanism of action
Secretolytic action on airway mucus
Ivy leaf extracts are classed as secretolytic expectorants, meant to make airway mucus easier to cough up. Animal studies after oral dosing report more tracheobronchial secretion, but the EU monograph states that the mechanism of action in people is not known.
Beta-2 receptor preservation (cell studies)
In cultured airway and lung cells, alpha-hederin reduced agonist-driven internalization of beta-2 adrenergic receptors and increased receptor binding and cAMP signaling. In theory this could aid bronchial relaxation, but it has not been measured in patients.
Hederacoside C and human exposure
Hederacoside C is the pharmacopoeial quality marker of the leaf. Rat studies showed low oral exposure to hederacoside C and alpha-hederin, and small human studies detected no or only trace alpha-hederin, so it is unclear how much of the cell-study compound reaches airway tissue.
Antispasmodic and anti-inflammatory effects in lab models
Isolated tissue and animal studies report antispasmodic, anti-inflammatory and cough-reducing effects of ivy preparations. These models explain research interest but do not show that the same effects occur at the doses people take.
Clinical trials
Randomized, double-blind, placebo-controlled, multicenter trial; ivy leaf dry extract EA 575 liquid 5 mL (35 mg extract) three times daily (105 mg/day) or placebo for 7 days, with follow-up to day 14. Primary outcome: cough severity on a visual analog scale over the treatment period. Sponsored by Engelhard Arzneimittel, the maker, which supplied the study product; two authors, including the sponsor's medical director, are affiliated with the company (Schaefer et al. 2016, Pharmazie)
181 adults with acute cough.
Cough severity, Bronchitis Severity Score and a verbal cough rating fell more with ivy extract than with placebo, with a difference seen within 48 hours that was still present 7 days after treatment ended. All adverse events were nonserious, mild or moderate, and judged not related to the extract.
Randomized, double-blind, placebo-controlled, multicenter, four-arm trial; EA 575 liquid 105 mg extract/day given as 5 mL three times daily or 7.5 mL twice daily, or matching placebo, for 1 week with 2 weeks of observation. Funded by Engelhard Arzneimittel, the maker; two authors are company employees (Schaefer et al. 2019, ERJ Open Res)
209 adults with acute bronchitis.
The Bronchitis Severity Score fell more with ivy extract than with placebo during and at the end of treatment, and cough severity and verbal cough ratings also favored the extract. The twice-daily and three-times-daily schemes did not differ.
Randomized, open-label, three-arm, multicenter trial at ten sites in Germany (3:2:2 allocation) in adults with acute bronchitis; EA 575 drops 50.4 mg extract/day vs ivy/thyme drops vs thyme/primrose drops, each per its label for 7 days, with no placebo group. Primary outcome: change in Bronchitis Severity Score from baseline to day 7, tested for non-inferiority and then superiority. Funded by Engelhard Arzneimittel, maker of EA 575; three authors are company employees. A published critique, whose writing support was funded by Bionorica SE, argued that the open-label design, patient-reported outcomes, unexplained unequal allocation and incomplete reporting cannot substantiate non-inferiority or superiority claims (Kardos et al. 2025, Pharmaceuticals (Basel))
325 adults treated at ten medical sites in Germany.
On the primary symptom score change by day 7, the single ivy extract was non-inferior to both combination products and scored better than the ivy/thyme drops; its advantage over the thyme/primrose drops did not reach significance. There was no placebo group. Adverse events were few, all nonserious, and comparable across groups. Patients and investigators knew which product was given.
Randomized, double-blind, placebo-controlled crossover trial in children with partly or poorly controlled mild persistent allergic asthma; 4 weeks of ivy leaf dry extract cough medicine or placebo added to inhaled corticosteroid (400 micrograms budesonide equivalent), with a washout between periods. Primary outcomes: relative change in FEV1 and MEF75-25 before bronchodilation. The abstract does not name a funder; PubMed lists non-government research support (Zeil et al. 2014, Phytomedicine)
30 children aged 6 to 11 on long-term inhaled steroid treatment.
The two primary outcomes (FEV1 and MEF75-25) showed no treatment effect in the crossover analysis. Some secondary flow and vital capacity readings rose after the ivy period but not after placebo. The authors called it a proof-of-concept study needing further trials.
Independent systematic review (searches December 2009 to January 2020) of ivy leaf alone or in combination for acute upper respiratory tract infections and bronchitis with cough in adults and children; the authors declare no industry conflicts (Sierocinski et al. 2021, Eur J Clin Pharmacol)
Six randomized trials, one controlled trial and four observational studies in adults and children.
Three randomized trials reported a faster fall in symptom severity or frequency with ivy leaf, but the reviewers judged the effects minimal at best and of uncertain clinical importance. Reporting quality was low and risk of bias high. No serious adverse effects were reported.
Systematic review of randomized, controlled and observational studies of ivy leaf for acute upper respiratory tract infections with cough (Holzinger et al. 2011, Evid Based Complement Alternat Med)
Ten studies with 17,463 participants testing ivy leaf alone (7 studies) or with thyme (3 studies).
Only two studies were randomized, and the single placebo-controlled trial (360 people) tested an ivy/thyme combination rather than ivy alone, which did better than placebo. All other studies lacked a placebo group and had serious design flaws, so the reviewers found no convincing evidence for ivy leaf.