Supplement analysis backed by scientific evidence · PT · ES · DE · FR

← All supplements
Limited evidenceImmunity

Marshmallow Root

Marshmallow root's mucilage forms a soothing film over an irritated throat, which is a plausible mechanism but has never been tested against placebo in a proper randomized trial. It is safe and cheap, and probably worth about what a cup of honey-lemon tea is worth.

View on iHerb Ships to 180+ countries · welcome discount for new customers

What the science says

  • Soothes dry, irritative cough and sore throat Limited evidence

    The root contains 5-11% polysaccharide mucilage that coats pharyngeal mucosa and physically blunts the cough reflex — a real mechanism, confirmed by bioadhesion assays. But the human evidence is two uncontrolled user surveys of a marshmallow syrup (n=822 and n=396) in which 86-95% of respondents rated it effective. Cough placebo response rates in controlled trials routinely run 60-85%, so uncontrolled satisfaction data like this cannot distinguish drug from expectation.

  • Anti-inflammatory action on mucosal tissue Limited evidence

    Aqueous marshmallow root extract inhibits human hyaluronidase-1 and reduces inflammatory mediator release in cultured macrophages at concentrations of roughly 0.1-1 mg/mL. These are cell-culture findings; no trial has measured inflammatory markers or mucosal healing in people taking marshmallow.

  • Helps gastritis, reflux, or 'leaky gut' Limited evidence

    A demulcent that coats the throat during a 10-second swallow is not established to coat the stomach or intestine, and no controlled trial has tested marshmallow root for gastritis, GERD, or intestinal permeability. The European Medicines Agency lists marshmallow root only as a 'traditional use' herbal, meaning efficacy is assumed from long use rather than demonstrated.

Dosage & safety

Studied doseTraditional and monograph doses: 2-5 g dried root as a cold-water infusion (cold maceration preserves mucilage better than boiling), up to 3 times daily; syrups typically 10 mL up to 6 times daily; lozenges around 20 mg dry extract. No dose-response data from controlled trials exist because those trials have not been done.
SafetyVery well tolerated; the main documented issue is pharmacokinetic rather than toxic. Mucilage can coat the gut and delay absorption of other oral medications, so take other drugs at least 30-60 minutes before or after. Syrups are often sugar-heavy — relevant for diabetics. Theoretical additive effect with blood-glucose-lowering drugs has been raised but not documented in humans. Not banned in sport; no hepatotoxicity signals.

How to take it

TimingTake it when the throat or gut is irritated — the soothing effect is local and short-lived, not cumulative.
With food?Between meals, and at least 30-60 minutes away from other oral medication.
Worth knowingMake it as a cold-water maceration over several hours; boiling degrades the mucilage that does the work.

Interactions

With medications

  • all oral medication

    The mucilage coats the gut lining and can delay or reduce absorption of anything taken at the same time. take other drugs at least 30-60 minutes before or after

With other supplements

  • other oral supplements

    Same mucilage-driven delay in absorption. separate by 30-60 minutes

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does marshmallow root help a cough or sore throat?

Marshmallow root's mucilage coats the throat and plausibly soothes a dry cough, but it has never been tested against placebo in a proper randomised trial (limited evidence). The human data are uncontrolled user surveys, which cannot separate the herb from placebo, since placebo cough responses often run 60-85%.

Is marshmallow root good for acid reflux or leaky gut?

No controlled trial has tested marshmallow root for gastritis, GERD or intestinal permeability, and coating the throat during a swallow is not shown to coat the stomach or intestine (limited evidence). The EMA lists it only as a traditional-use herbal.

How do you make and take marshmallow root tea?

Monograph doses of marshmallow root are 2-5 g of dried root as a cold-water infusion, up to 3 times daily; cold maceration over several hours preserves the mucilage better than boiling. The soothing effect is local and short-lived, so take it when your throat is irritated.

Does marshmallow root interfere with medications?

Marshmallow root mucilage can coat the gut and delay or reduce absorption of other oral medications and supplements. Take other drugs at least 30-60 minutes before or after marshmallow root.

Scientific references

Where to buy

Nature's Answer, Marshmallow Root Fluid Extract, Alcohol-Free, 2,000 mg, 1 fl oz (30 ml)

View on iHerb

Ships to 180+ countries · welcome discount for new customers

Referral link — this site may earn a commission on purchases.

Related in Immunity