Natural Remedies, Herbs and Supplements for Cough, Ranked by Evidence
The natural remedies with the best evidence for a cough are honey, ivy leaf extract and thyme, usually as a thyme-ivy or thyme-primrose syrup. Honey reduced cough frequency and severity more than usual care and dextromethorphan in a 2021 meta-analysis of 14 trials and a 2018 Cochrane review in children; ivy leaf extract EA 575 cut bronchitis severity scores more than placebo in a 2016 trial of 181 adults; and thyme-ivy syrup reduced coughing fits by about 50 percent within 10 days in a 361-patient trial. Pelargonium sidoides and N-acetylcysteine have moderate evidence for the chesty, productive cough of bronchitis.
This guide is for the acute cough that follows a cold or flu, dry or chesty, in adults and children over one. Most of these coughs last two to three weeks whatever you do, and the aim is fewer coughing fits, looser mucus and better sleep, not a shorter illness. We separate demulcents (which coat), expectorants (which thin mucus) and anti-inflammatories, because the right pick depends on what kind of cough you have. Honey is not in our library so it is covered in the lifestyle section, but for most people it is the first thing to reach for.
See a clinician if a cough lasts more than 3 weeks, brings up blood or rust-coloured sputum, comes with breathlessness, chest pain, high fever, wheeze, night sweats or weight loss, or if you are a smoker over 40 with a change in your usual cough. In babies under one, a cough with fast breathing, feeding difficulty or a whooping sound needs same-day assessment. Chronic cough is a different problem, most often asthma, reflux or post-nasal drip, and needs a diagnosis rather than a syrup.
Quick answer
- Honey — reduced cough frequency and severity more than usual care in a 2021 meta-analysis of 14 trials; 1–2 teaspoons at bedtime
- Ivy leaf (Hedera helix EA 575) — bronchitis severity scores fell more than placebo in a 181-adult RCT; 35 mg extract 2–3 times daily
- Thyme (with ivy or primrose) — coughing fits halved within 10 days versus placebo in RCTs of 361 and 150 patients
- Pelargonium sidoides — probably shortens acute bronchitis by about 2 days (Cochrane 2013)
- N-acetylcysteine — 600 mg/day cut flare-ups of chronic bronchitis by about 25% in meta-analyses
- Andrographis — reduced cough and other cold symptoms versus placebo in a 2017 meta-analysis of 33 trials
The 9 best herbs and supplements for cough
Ranked by the strength of human evidence. Strong = multiple trials or a meta-analysis. Moderate = a few small trials. Preliminary = early or animal data.
Ivy leaf saponins, mainly alpha-hederin, relax bronchial smooth muscle and thin mucus by acting on beta-2 receptors, and the extract is a licensed cough medicine across Europe. A 2016 placebo-controlled trial of 181 adults with acute bronchitis found ivy extract EA 575 reduced the bronchitis severity score significantly more than placebo at day 7, and a 2011 systematic review of 10 trials in more than 17,000 patients found consistent improvement in cough and sputum with very few side effects. The 2016 trial is the best single piece of evidence for any cough herb.
- Key evidence
- Schaefer 2016 placebo-controlled RCT of EA 575 (n=181); systematic review of 10 trials (Holzinger 2011)
- Studied dose
- 35 mg of dried ivy leaf extract (EA 575) 2–3 times daily as syrup or tablet for 7 days; children 2–5 years 2.5 mL syrup three times daily
- Best for
- A chesty cough with thick mucus that is hard to bring up
- Cautions
- Can cause mild nausea or loose stools. Rare allergic skin reactions. Not studied in pregnancy; avoid under 2 years because any mucus-thinning agent can worsen airway obstruction in infants.
This South African geranium root extract stops bacteria adhering to airway cells and boosts ciliary beat frequency. A 2013 Cochrane review of 10 randomised trials (8 in adults, 2 in children) found Pelargonium probably shortens acute bronchitis and reduces symptoms, with the liquid form working better than tablets, and rated the certainty low mainly because the trials came from one manufacturer. A 2008 trial of 406 adults found about 2 days faster resolution of bronchitis symptoms with the 30-drop dose versus placebo.
- Key evidence
- Cochrane review 2013 (10 RCTs); Matthys 2008 dose-finding RCT (n=406)
- Studied dose
- 30 drops (1.5 mL) of EPs 7630 three times daily for adults, 20 drops for children 6–12, 10 drops for 1–5, for 7–10 days
- Best for
- Acute bronchitis: a chesty cough following a cold, with or without sore throat
- Cautions
- Rare reports of liver injury and allergic reactions; stop if you develop jaundice, dark urine or rash. Theoretical additive effect with warfarin. Avoid in pregnancy and breastfeeding for lack of data.
Thyme contains thymol and flavonoids that relax bronchial muscle and have mild antimicrobial and expectorant effects. In a 2006 German trial of 361 adults with acute bronchitis, a thyme-ivy syrup reduced coughing fits by 50 percent after 10 days versus 38 percent on placebo, reaching that halving about 2 days sooner; a 2007 trial of 150 patients found a thyme-primrose root syrup produced a similar advantage. Thyme on its own is approved by the European Medicines Agency as a traditional expectorant, but the trials are for the combinations, so buy those.
- Key evidence
- Kemmerich 2006 RCT thyme-ivy (n=361) and Kemmerich 2007 RCT thyme-primrose (n=150)
- Studied dose
- Thyme-ivy or thyme-primrose syrup 5.4 mL three times daily for 10 days; or thyme tea from 1–2 g dried herb three times daily
- Best for
- A productive cough with frequent coughing fits during the day
- Cautions
- Thyme essential oil is toxic internally; use syrups and teas only. Possible allergy in people sensitive to oregano and other Lamiaceae. Culinary amounts are fine in pregnancy; medicinal doses have no data.
Andrographolide is anti-inflammatory and immune-modulating, and andrographis has the largest trial literature of any herb for upper respiratory infections. A 2017 meta-analysis of 33 randomised trials with 7,175 patients found it improved cough, sore throat and overall symptoms versus placebo and reduced symptom duration, though trial quality was mixed and most came from China and Scandinavia. A 2004 trial of 185 adults found the Kan Jang andrographis-eleuthero combination roughly halved cough and nasal symptoms by day 5.
- Key evidence
- Hu 2017 meta-analysis of 33 RCTs (n=7,175)
- Studied dose
- Extract standardised to 60–90 mg andrographolides a day in 2–3 divided doses, started early, for 5–7 days
- Best for
- A cough that is part of an all-over cold with sore throat and fatigue
- Cautions
- Bitter and can cause nausea and loss of appetite. Avoid in pregnancy (animal data suggest it can end pregnancy) and in autoimmune disease or with immunosuppressants. May add to blood-pressure and anticoagulant drugs. Rare allergic reactions.
N-acetylcysteine (NAC)
Moderate evidenceNAC breaks the disulphide bonds in mucus, making it thinner and easier to cough up, and it is a licensed mucolytic in many countries. A 2015 Cochrane review of mucolytics in chronic bronchitis and COPD (30 trials) found about 25 percent fewer exacerbations with regular use, and a 2015 meta-analysis of 13 trials found 600 mg twice daily reduced flare-ups in COPD. For a short acute cough, the evidence is thinner: trials in acute bronchitis show modest improvements in sputum but little change in cough duration, so its real strength is in people with a chronic chesty cough.
- Key evidence
- Cochrane review of mucolytics in chronic bronchitis/COPD 2015 (30 trials); Cazzola 2015 meta-analysis
- Studied dose
- 600 mg once or twice daily; chronic bronchitis trials used 600 mg twice daily for 6–12 months
- Best for
- Smokers, ex-smokers and people with chronic bronchitis or recurrent chest infections
- Cautions
- Nausea, loose stools and a sulphur smell. May increase the effect of nitroglycerin and anticoagulants slightly. Avoid in active peptic ulcer, and ask your doctor if you have asthma, since rare bronchospasm has been reported with inhaled forms.
Cineole, the main component of eucalyptus oil, is anti-inflammatory in the airways and increases mucus clearance. In a 2009 trial of 242 patients with acute bronchitis, 200 mg of cineole capsules three times daily reduced the bronchitis severity score and cough frequency significantly more than placebo by day 4, and a 2012 trial found it reduced exacerbations in COPD over 6 months. Cineole capsules are not available everywhere; inhaled eucalyptus vapour is popular but has not been tested in the same way and is not the same dose.
- Key evidence
- Fischer and Dethlefsen 2013 RCT of cineole in acute bronchitis (n=242); Worth 2009 RCT in COPD
- Studied dose
- 200 mg of 1,8-cineole in enteric capsules three times daily for 10 days; or 2–3 drops of eucalyptus oil in a bowl of hot water for steam inhalation
- Best for
- A chesty cough with blocked sinuses and a tight chest
- Cautions
- Never swallow eucalyptus oil itself: as little as 3–5 mL has caused seizures and death. Do not apply oil or menthol rubs to the face of children under 2. Avoid in pregnancy and with liver disease. May increase metabolism of some drugs through CYP induction.
Zinc lozenges
Preliminary evidenceZinc acts on rhinovirus in the throat rather than in the chest, so it helps the cold that causes the cough rather than the cough itself. A 2017 meta-analysis of zinc acetate lozenges found colds were 33 percent shorter, with cough resolving about 46 percent faster in one of the trials, and a 2024 Cochrane review of 34 trials found zinc may shorten colds by around 2 days with low certainty. It needs to be started within 24 hours of the first symptoms, which is usually before the cough begins.
- Key evidence
- Hemilä 2017 meta-analysis of zinc acetate lozenges; Cochrane 2024 (34 trials)
- Studied dose
- Lozenges giving 13–23 mg elemental zinc every 2–3 hours while awake (75–90 mg/day), for up to 7 days from first symptoms
- Best for
- Day one of a cold, before the cough starts
- Cautions
- Nausea and metallic taste; limit to 7 days to avoid copper depletion. Separate from quinolone and tetracycline antibiotics by 2 hours. Never use zinc nasal sprays.
Marshmallow root is a mucilage demulcent with a European Medicines Agency monograph for dry irritative cough: it coats the pharynx and reduces the cough reflex triggered by irritation at the back of the throat. A 2018 German observational study of 822 patients found marshmallow syrup or lozenges relieved dry cough within 10 minutes in most people and were well tolerated, but there was no placebo arm. Laboratory work shows the polysaccharides reduce inflammatory signalling in airway cells. It does nothing for mucus in the chest.
- Key evidence
- EMA herbal monograph; Fink 2018 observational study (n=822)
- Studied dose
- Syrup 10 mL up to 6 times daily, or 2–5 g root as a cold infusion three times daily; lozenges as needed
- Best for
- A dry, tickly cough that keeps you awake, including in pregnancy
- Cautions
- May slow absorption of other medicines taken at the same time; separate by 1–2 hours. May lower blood sugar slightly. Check sugar content of syrups.
Licorice is a demulcent and glycyrrhizin has anti-inflammatory and antiviral effects, which is why it appears in most traditional cough formulas and in Throat Coat-type teas. The human cough data are indirect: it reduces post-operative sore throat and cough after intubation in several anaesthesia trials, including a 236-patient trial that roughly halved post-extubation coughing, and it is a component of several Chinese and Japanese cough preparations tested in small trials. There are no good trials of licorice alone for the cough of a cold.
- Key evidence
- Ruetzler 2013 RCT on post-extubation cough (n=236); traditional-use monographs
- Studied dose
- 1–2 g of dried root as tea up to three times daily, or lozenges with 10–20 mg glycyrrhizin, for no more than 1–2 weeks
- Best for
- A dry cough with a raw throat, for short-term use
- Cautions
- Regular glycyrrhizin raises blood pressure and lowers potassium; avoid in hypertension, heart failure, kidney disease and pregnancy, and with diuretics, digoxin or corticosteroids. DGL forms avoid this but are not demulcent in the same way.
How to choose
- For almost any cough, start with honey (1 to 2 teaspoons, especially at bedtime), fluids and steam. It has the best evidence per dollar of anything here.
- If the cough is chesty with thick mucus, choose an expectorant: ivy leaf extract or a thyme-ivy syrup, and keep well hydrated so the thinner mucus can move.
- If the cough is dry and tickly, coating is what you want: marshmallow root or a slippery elm-based lozenge, with honey. Expectorants will not help a cough that produces nothing.
- If the cough came with a full-blown cold, sore throat and sinus congestion, Pelargonium or andrographis treats the whole infection; add zinc lozenges only if you are within 24 hours of the first symptom.
- If you have chronic bronchitis, COPD or a cough every winter, NAC 600 mg twice daily over the winter reduces flare-ups and is worth discussing with your doctor.
- If the cough has lasted more than 3 weeks, stop buying syrups and get a diagnosis. Post-viral cough, asthma, reflux, post-nasal drip and ACE-inhibitor side effects each need a different treatment.
What to skip
Over-the-counter cough syrups (dextromethorphan, guaifenesin) for children
A 2014 Cochrane review found no good evidence they work in acute cough, and honey beat dextromethorphan in paediatric trials. The FDA advises against them under 4 and many countries restrict them under 6 because of overdose risk.
Mullein and elecampane
Both are traditional lung herbs and widely sold as 'lung tonics', but neither has a single randomised trial in people for cough. They are probably harmless as teas; just do not pay a premium for them when ivy leaf and thyme have actual data.
Essential oil taken by mouth
Eucalyptus, oregano and peppermint oils are toxic when swallowed. Eucalyptus oil has caused seizures in children at teaspoon doses. The trials used purified cineole in enteric capsules, not the bottle in the aromatherapy aisle.
Antibiotics for a cough with green phlegm
Colour does not mean bacteria. A Cochrane review of 17 trials found antibiotics shortened acute bronchitis by about half a day at the cost of side effects and resistance. They are for pneumonia, whooping cough and people with COPD flare-ups, not a chesty cold.
Safety and when to see a clinician
- See a clinician if the cough lasts more than 3 weeks, brings up blood, or comes with breathlessness, chest pain, fever over 38.5 C for more than 3 days, wheeze, night sweats or weight loss. A new or changed cough in a smoker over 40 needs a chest X-ray.
- In children, same-day assessment for fast or laboured breathing, a whooping or barking cough, grunting, blue lips, feeding difficulty, or any cough in a baby under 3 months.
- Never give honey under 12 months. Do not use mucolytics such as ivy leaf or NAC under 2 years, and avoid menthol or eucalyptus rubs on the faces of children under 2.
- Licorice with glycyrrhizin raises blood pressure and lowers potassium; avoid regular use with antihypertensives, diuretics, digoxin and in pregnancy. Andrographis is contraindicated in pregnancy and with immunosuppressants. Pelargonium has rare liver reports.
- NAC, andrographis and Pelargonium may add slightly to warfarin and other anticoagulants; check INR if you start one while on warfarin. Zinc lozenges need separating from tetracycline and quinolone antibiotics by 2 hours.
- In pregnancy, honey, steam, marshmallow root and thyme tea in culinary amounts are the safest options. Avoid andrographis, eucalyptus oil, medicinal licorice and high-dose zinc, and ask your midwife before Pelargonium or ivy leaf.
What matters as much as any herb
- Honey at bedtime: in a 2018 Cochrane review of 6 paediatric trials, honey reduced cough frequency and improved sleep more than no treatment, placebo and diphenhydramine, and about as well as dextromethorphan. Adults respond the same way. Use 1 to 2 teaspoons, neat or in warm water, from age 1.
- Fluids and steam: mucus that is well hydrated moves; mucus that is dry sticks. Drink steadily, breathe steam from a bowl or shower, and run a humidifier at night. A hot drink alone improved cough, runny nose and sneezing within minutes in a 2008 trial.
- Sleep propped up: lying flat lets post-nasal drip pool on the larynx and triggers coughing. Raise the head of the bed or use an extra pillow for the duration.
- Avoid smoke and irritants: cigarette smoke, wood smoke and strong fragrances prolong a cough by keeping the airway inflamed. If you smoke, a chest infection is a reasonable moment to stop.
- Treat the cause of a chronic cough: post-nasal drip responds to saline rinses and antihistamines, reflux to the measures in our acid reflux guide, and asthma to an inhaler. No syrup fixes an undiagnosed cause.
Frequently asked questions
What is the best natural cough suppressant?
Honey. Across a 2021 meta-analysis of 14 trials and a 2018 Cochrane review in children, it reduced cough frequency and severity more than usual care and at least as well as dextromethorphan, the main over-the-counter suppressant. For a dry tickly cough, add a demulcent such as marshmallow root; for a chesty one, you want an expectorant rather than a suppressant.
What is the best natural expectorant?
Ivy leaf extract and thyme-ivy syrup have the best trial evidence for loosening mucus and reducing coughing fits in acute bronchitis. N-acetylcysteine is the strongest option for people with chronic bronchitis or COPD. Staying well hydrated and breathing steam are the non-herb equivalents.
Does honey really work for a cough?
Yes, with better evidence than most cough medicines. It coats the throat, has mild antimicrobial activity and may work partly through the sweetness triggering saliva and endogenous opioids that dampen the cough reflex. One to two teaspoons at bedtime improved both cough and sleep in children in multiple trials. Never give it to babies under one.
How long should a cough last after a cold?
Longer than most people expect: the average acute cough lasts about 18 days, and a cough that lingers 3 to 4 weeks after a cold is common and usually post-viral. Beyond 8 weeks it is defined as chronic and needs a diagnosis, most often asthma, reflux, post-nasal drip or a medication side effect.
Is thyme good for a cough?
Thyme is one of the few herbs with randomised trials for cough. A thyme-ivy syrup halved coughing fits about 2 days faster than placebo in a 361-patient trial, and a thyme-primrose syrup did similar. Thyme tea is a reasonable home version, but the trials used standardised syrups, so buy those if you can.
Can I take NAC for a cough?
NAC thins mucus and is a licensed mucolytic. It clearly reduces flare-ups in chronic bronchitis and COPD at 600 mg twice daily, but for a short cough after a cold the benefit is modest. It is worth trying if you have a lot of thick phlegm, and it is well tolerated apart from nausea and a sulphur smell.
When is a cough serious?
When it brings up blood, comes with breathlessness, chest pain, high fever, wheeze, night sweats or weight loss, lasts more than 3 weeks, or changes in character in a smoker. In babies and small children, fast breathing, grunting, a whooping sound or blue lips need urgent care. Whooping cough is on the rise and can look like an ordinary cold in the first week.
References
- Abuelgasim H, Albury C, Lee J. Effectiveness of honey for symptomatic relief in upper respiratory tract infections: a systematic review and meta-analysis. BMJ Evidence-Based Medicine (2021)View source
- Oduwole O, Udoh EE, Oyo-Ita A, Meremikwu MM. Honey for acute cough in children (Cochrane Review). Cochrane Database of Systematic Reviews (2018)View source
- Schaefer A, Kehr MS, Giannetti BM, Bulitta M, Staiger C. A randomized, double-blind, placebo-controlled, multicentre trial to evaluate the efficacy and safety of a liquid containing ivy leaves dry extract (EA 575) vs. placebo in the treatment of adults with acute cough. Pharmazie (2016)View source
- Kemmerich B, Eberhardt R, Stammer H. Efficacy and tolerability of a fluid extract combination of thyme herb and ivy leaves and matched placebo in adults suffering from acute bronchitis with productive cough. A prospective, double-blind, placebo-controlled clinical trial. Arzneimittelforschung (2006)View source
- Kemmerich B. Evaluation of efficacy and tolerability of a fixed combination of dry extracts of thyme herb and primrose root in adults suffering from acute bronchitis with productive cough. A prospective, double-blind, placebo-controlled multicentre clinical trial. Arzneimittelforschung (2007)View source
- Timmer A, Günther J, Motschall E, et al.. Pelargonium sidoides extract for treating acute respiratory tract infections (Cochrane Review). Cochrane Database of Systematic Reviews (2013)View source
- Hu XY, Wu RH, Logue M, et al.. Andrographis paniculata (Chuān Xīn Lián) for symptomatic relief of acute respiratory tract infections in adults and children: A systematic review and meta-analysis. PLoS One (2017)View source
- Poole P, Chong J, Cates CJ. Mucolytic agents versus placebo for chronic bronchitis or chronic obstructive pulmonary disease (Cochrane Review). Cochrane Database of Systematic Reviews (2015)View source
- Fischer J, Dethlefsen U. Efficacy of cineole in patients suffering from acute bronchitis: a placebo-controlled double-blind trial. Cough (2013)View source
- Nault D, Machingo TA, Shipper AG, et al.. Zinc for prevention and treatment of the common cold (Cochrane Review). Cochrane Database of Systematic Reviews (2024)View source
- Smith SM, Schroeder K, Fahey T. Over-the-counter (OTC) medications for acute cough in children and adults in community settings (Cochrane Review). Cochrane Database of Systematic Reviews (2014)View source
- Cough. NHS (2024)View source
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Ask about coughThis guide is educational and is not medical advice. Herbs and supplements can interact with prescription medicines and are not regulated like drugs. Talk with a clinician or pharmacist before starting anything new, especially if you are pregnant, breastfeeding, have a chronic condition, or take medication.