Condition
Acute Bronchitis
Acute bronchitis is a chest infection, usually caused by a virus, and its cough typically lasts about two to three weeks. Antibiotics shortened that cough by only about half a day in trials and caused more side effects. Among supplements, a Cochrane review found that a liquid Pelargonium sidoides root extract eased acute bronchitis symptoms in adults and children, but it rated the evidence low. Honey eased cough more than usual care in upper airway infections, and ivy leaf showed minimal effects at best. N-acetylcysteine (NAC) was tested mainly in chronic bronchitis and COPD, and those trials disagree. See a clinician if you are short of breath or the cough lasts beyond three weeks.
Sources: PMID 27929206; PMID 28626858; PMID 24146345; PMID 32817011; PMID 33523253; PMID 31598901; PMID 36927162; PMID 15866309; PMID 29080708
- Supplements studied
- 3
- Graded outcomes
- 4
- Trials
- 10
- People studied
- 9,867
What the evidence says
- Pelargonium sidoides (a South African geranium) root extract, which our database grades A for acute bronchitis symptoms: a Cochrane review rated the evidence low. In 3 trials with 746 adults, a liquid extract eased most symptoms but tablets did not, and 3 trials with 819 children showed similar results. The reviewers suspected that some negative studies went unpublished. An earlier review pooled 4 placebo-controlled trials and found lower symptom scores by day 7. In one trial of 468 adults, 16% of those on the liquid extract were still unable to work after 7 days, against 43% on placebo.
- Honey for cough: limited evidence. A review of 14 studies in upper airway infections found that honey eased how often and how hard people coughed more than usual care did; in the 2 studies against placebo there was no clear difference. A Cochrane review of 6 trials in children aged 12 months to 18 years found honey probably eased cough more than no treatment or placebo, and about as well as dextromethorphan, a common cough medicine. Most children were treated for one night only.
- Ivy leaf: very limited evidence. A 2021 review found 6 randomized trials of ivy leaf for cough from upper airway infections and bronchitis. Three reported faster easing of cough, but the reviewers judged the effects minimal at best, with low-quality reporting and a high risk of bias. An earlier review of herbal cough remedies pooled 4 trials of ivy, primrose or thyme products and found them better than placebo for cough in colds and upper airway infections.
- Antibiotics, for comparison: a Cochrane review of 17 trials with 5,099 people with acute bronchitis found no difference in how many had improved at follow-up. The cough ended about half a day sooner on antibiotics, and side effects were more common. A clinical review notes that acute bronchitis is usually caused by viruses and that antibiotics are not indicated in people without chronic lung disease.
- N-acetylcysteine (NAC) in chronic bronchitis and COPD: mixed evidence. Our database's B grade for NAC comes from a review of 11 studies in chronic bronchitis (775 people on NAC, 789 on placebo) that found fewer flare-ups and better symptoms; its authors suggested under 1,200 mg a day for at least 3 months. But a 2023 review of 9 placebo-controlled trials in COPD found no drop in flare-ups, and a 3-year trial of 600 mg a day in 523 people with COPD found no effect on flare-ups or lung function. A Cochrane review of 38 trials of mucus-thinning medicines, NAC among them, found a small drop in flare-ups that was smaller in recent trials. We found no trials of NAC in adults with acute bronchitis.
- We found no trials of slippery elm for cough or bronchitis. Our database's D grade for slippery elm reflects traditional use as a throat-coating remedy, not trial results.
Safety and when to see a clinician
- See a clinician soon if you are short of breath, breathing fast or have a racing heart, because these can point to pneumonia, which needs a chest X-ray. A cough that comes in fits, ends in a whoop or makes you vomit, and has lasted more than 2 weeks, can be whooping cough (pertussis). The cough of acute bronchitis usually lasts about 2 to 3 weeks; a guideline from lung specialists no longer classes a cough that lasts more than 3 weeks as acute, so get it checked.
- Get urgent care if you cough up blood, have chest pain, a high fever or confusion, or your lips turn blue. If you have asthma, COPD, heart disease or a weakened immune system, or are older and frail, see a clinician early rather than treating yourself.
- Never give honey, including honey cough syrups, to a baby under 12 months old. Honey can carry the bacterial spores that cause infant botulism, and health authorities advise against honey before 12 months.
- Pelargonium: in trials, side effects were more common than with placebo, but none were serious, and a 24-week trial in COPD saw more mild stomach and gut complaints. The drug commission of the German Medical Association read reports of liver injury in people taking it as a sign that it might harm the liver. A review of 15 of these reports found no case where Pelargonium was a probable cause, but the case data were poor. Stop it and see a doctor if your skin or eyes turn yellow or your urine turns dark.
- A cough with phlegm that keeps coming back for months is not acute bronchitis. It needs a diagnosis and prescribed treatment, and NAC is not a replacement for inhalers. In the chronic bronchitis review, NAC caused no more side effects than placebo.
Evidence by supplement
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Bronchitis Symptoms Moderate Improvement | Improves (the measure goes down) | Moderate effect | 4 studies | 1,012 people | ||
Studies that measured bronchitis symptoms
| ||||||
| Appetite Small Increase | Worsens (the measure goes up) | Small effect | 620 people | |||
| Lung Function | Improves (the measure goes up) | 10 studies | 4,241 people | |||
Studies that measured lung function
| ||||||
| Fever | Improves (the measure goes up) | 2 studies | 3,237 people | |||
Studies that measured fever | ||||||
| Common Cold Symptoms | Changes; see studies | 1 study | 693 people | |||
Studies that measured common cold symptoms | ||||||
| Cough | Changes; see studies | 1 study | 719 people | |||
| Fatigue Symptoms | Changes; see studies | 3,641 people | ||||
| Headaches | Changes; see studies | 4,261 people | ||||
| Nausea Symptoms | Changes; see studies | 620 people | ||||
| Subjective Well-Being | Improves (the measure goes up) | 1,111 people | ||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Bronchitis Symptoms Small Improvement | Improves (the measure goes down) | Small effect | 1 study | 968 people | ||
Studies that measured bronchitis symptoms | ||||||
| Chronic Bronchitis | Improves (the measure goes up) | 1,564 people | ||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Cough Symptom Relief No clinical trials evaluate slippery elm for cough suppression or relief. Traditional use as a demulcent for coughs is long-standing, and the mucilage coating mechanism is plausible for soothing irritated upper airways, but no modern clinical data supports this indication specifically. | Improves (the measure goes down) | Small effect |
Key findings
- Bronchitis SymptomsImproves (the measure goes down)
- AppetiteWorsens (the measure goes up)
- Cough Symptom ReliefImproves (the measure goes down)
The Acute Bronchitis Support protocol
2 primary supplements · 7 supporting supplements
- Pelargonium sidoides (Umckaloabo)EPs 7,630 extract: 30 drops or 1.5 mL 3 times daily for 7–14 days
- N-Acetylcysteine (NAC)600–1,200 mg daily in divided doses
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Studies cited
22 studies from PubMed
- Acute Bronchitis.
- Antibiotics for acute bronchitis.
- Pelargonium sidoides extract for treating acute respiratory tract infections.
- Effectiveness of honey for symptomatic relief in upper respiratory tract infections: a systematic review and meta-analysis.
- Ivy leaf (Hedera helix) for acute upper respiratory tract infections: an updated systematic review.
- Effect of Orally Administered N-Acetylcysteine on Chronic Bronchitis: A Meta-analysis.
- The efficacy of N-acetylcysteine in chronic obstructive pulmonary disease patients: a meta-analysis.
- Effects of N-acetylcysteine on outcomes in chronic obstructive pulmonary disease (Bronchitis Randomized on NAC Cost-Utility Study, BRONCUS): a randomised placebo-controlled trial.
- Classification of Cough as a Symptom in Adults and Management Algorithms: CHEST Guideline and Expert Panel Report.
- Pelargonium sidoides for acute bronchitis: a systematic review and meta-analysis.
- Efficacy and safety of an extract of Pelargonium sidoides (EPs 7630) in adults with acute bronchitis. A randomised, double-blind, placebo-controlled trial.
- Honey for acute cough in children.
- Herbal Medicine for Cough: a Systematic Review and Meta-Analysis.
- Mucolytic agents versus placebo for chronic bronchitis or chronic obstructive pulmonary disease.
- Association between honey consumption and infant botulism.
- Infant Botulism and Honey Exposure: Global Epidemiology, Prevention Policies, and Communication Strategies.
- Randomised, double-blind, placebo-controlled trial of EPs 7630 in adults with COPD.
- Spontaneous reports of primarily suspected herbal hepatotoxicity by Pelargonium sidoides: was causality adequately ascertained?
- Treatment of acute bronchitis in adults with a pelargonium sidoides preparation (EPs 7630): a randomized, double-blind, placebo-controlled trial.
- Treatment of acute bronchitis with a liquid herbal drug preparation from Pelargonium sidoides (EPs 7630): a randomised, double-blind, placebo-controlled, multicentre study.
- Efficacy and tolerability of EPs 7630 tablets in patients with acute bronchitis: a randomised, double-blind, placebo-controlled dose-finding study with a herbal drug preparation from Pelargonium sidoides.
- Effects of Pelargonium sidoides extract EPs 7630 on acute cough and quality of life - a meta-analysis of randomized, placebo-controlled trials.