Marshmallow Root
Summary
Marshmallow root is a mucilage-rich herb that EU regulators accept, on long-standing use alone, for throat irritation with dry cough and for mild stomach discomfort. No randomised trial has tested it alone by mouth; small trials of a vaginal cream and a skin ointment, plus a user survey of cough products, are the main human data.
Key facts
- The EMA's 2016 EU herbal monograph lists marshmallow root as a traditional herbal medicine, based on long-standing use rather than trials, for oral or throat irritation with dry cough and for mild gastrointestinal discomfort.[1]
- No randomised trial of marshmallow alone by mouth was found. Trials tested a vaginal cream added to clotrimazole (100 women), a 1% skin ointment in children (22 completers) and multi-herb products.[2][3][5]
- The EMA advises keeping marshmallow ½–1 hour apart from other medicines because it may delay their absorption.[1]
- The root contains polysaccharide mucilage built from rhamnose, galactose, galacturonic acid and glucuronic acid.[6]
- The EMA monograph does not recommend it under age 3, solid forms under age 6, the tea for stomach discomfort under 12, or the ethanol liquid extract under 18.[1]
- 3 graded human outcomes on this page
- October 13, 2026
How it works
ProposedThe root's polysaccharide mucilage is thought to coat irritated mucous membranes, which is why the EMA classes marshmallow preparations as demulcents for throat irritation and stomach discomfort. The same coating is the likely reason the EMA flags delayed absorption of other medicines. No human mechanistic studies were found.[6][1]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Cough and throat | Grade D | Improved | Observational · n = 822 · 2018 | 1 row |
| Vaginal symptoms | Grade D | Improved | RCT · n = 100 · 2023 | 1 row |
| Skin | Grade D | Improved | Pilot RCT · n = 22 · 2021 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| User-rated relief of dry cough and throat irritation | Improved | Grade D | Observational · n = 822 · 2018 Pharmacy customers buying marshmallow lozenges or syrup for dry cough Form: Aqueous marshmallow root extract (STW42) lozenges or syrup · Dose: As used per product label · Duration: 7 days Users reported good relief of throat irritation and dry cough, often within 10 minutes; 3 minor adverse events were reported with the syrup. | 30064132 (opens PubMed)Source [4] |
| Vulvovaginal yeast infection symptoms (vaginal cream added to clotrimazole) | Improved | Grade D | RCT · n = 100 · 2023 Women with vulvovaginal candidiasis (Iran) Form: 4% aqueous marshmallow extract with 1% clotrimazole vaginal cream (topical) · Dose: Applied nightly · Duration: 7 nights; follow-up at 7 and 30 days Compared with clotrimazole cream alone, the combination cream reduced itching and painful intercourse at both follow-ups and painful urination at day 7; neither cream caused significant adverse events. | 37121836 (opens PubMed)Source [2] |
| Atopic dermatitis severity in children (1% ointment) | Improved | Grade D | Pilot RCT · n = 22 · 2021 Children aged 3 months to 12 years with mild-to-moderate atopic dermatitis (Iran); 22 completed Form: 1% marshmallow ointment (topical) vs 1% hydrocortisone ointment · Dose: Twice daily for 1 week, then 3 times a week · Duration: 4 weeks SCORAD scores fell in both groups; the marshmallow group's improvement from baseline was significant (P = .015). There was no placebo arm. | 33034099 (opens PubMed)Source [3] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Dried root as a cold macerate or tea | Varies[1] | The EMA monograph uses 0.5–3 g of root soaked in 150 ml of water as a cold macerate (used straight after preparation) for throat irritation, or 2–5 g as tea for stomach discomfort. Absorption studies were not required for traditional-use status, and none were found.[1] | The EMA lists no known adverse effects; allergic reactions are reported rarely.[1][6] | Traditional use for throat irritation with dry cough and mild stomach discomfort (no trials) |
| Syrups, lozenges and aqueous extracts | Varies[1] | The EMA monograph covers an aqueous dry extract (3–9:1), water and ethanol liquid extracts, and syrup made from a macerate; no human absorption data were found.[1] | In 822 users of lozenges or syrup over 7 days, 3 minor adverse events were reported, all with the syrup.[4] | Dry cough and throat irritation (user survey) |
| Topical cream or ointment | Varies[2][3] | Applied to skin or vaginal tissue; absorption into the body was not measured.[2][3] | Neither a 4% vaginal cream (7 nights) nor its comparator caused significant adverse events.[2] | Vaginal yeast infection symptoms (with clotrimazole) and childhood atopic dermatitis |
Studied doses
Doses studied in human trials ranged from a 1% skin ointment in children (4 weeks) to a 4% vaginal cream (7 nights); no oral dose has been tested in a randomised trial. For reference, the EMA's traditional-use monograph lists 0.5–3 g of dried root as a cold macerate several times a day for adults with dry cough (maximum 15 g a day) and 2–5 g as tea three times a day for mild stomach discomfort.[3][2][1]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Oral medicines in generalDrug labelEMA monograph: absorption of medicines used at the same time may be delayed, so it advises keeping marshmallow ½–1 hour apart from them. No specific interaction has been reported.[1]
Who should be careful
- Pregnancy and breastfeeding
- Safety has not been established, and the EMA does not recommend use in pregnancy or breastfeeding. LactMed found no data on transfer into breast milk; oral use as a milk booster has no valid trials.[1][6]
- Children
- Not recommended under age 3; solid forms not under age 6; the tea for stomach discomfort not under 12; the ethanol liquid extract not under 18.[1]
- Allergy to marshmallow
- Hypersensitivity is the only contraindication in the EMA monograph; allergic reactions are rare.[1][6]
- Cough with breathlessness, fever or coloured phlegm
- The EMA monograph says these need assessment by a doctor or qualified health practitioner, as do symptoms lasting longer than 1 week (cough) or 2 weeks (stomach).[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Frequently asked questions
Does marshmallow root help a cough?
EU regulators accept it as a traditional remedy for throat irritation with dry cough, based on long-standing use rather than trials. The only cough data found were two uncontrolled surveys of 822 pharmacy customers who reported fast relief from lozenges or syrup.[1][4]
Is there a clinical trial of marshmallow root supplements?
Not of marshmallow alone by mouth. Randomised trials used a 4% vaginal cream added to clotrimazole and a 1% skin ointment in children, and a multi-herb product containing marshmallow (238 children with tonsillitis, open-label).[2][3][5]
Can marshmallow root affect other medicines?
Possibly. The EMA says it may delay absorption of medicines used at the same time and advises a gap of ½–1 hour; no specific interaction has been reported.[1]
Sources
- [1]European Union herbal monograph on Althaea officinalis L., radix (EMA/HMPC/436679/2015). European Medicines Agency (HMPC), 2016. guideline
- [2]The efficacy of complementary treatment with marshmallow (Althaea officinalis L.) on vulvovaginal candidiasis: A randomized double-blinded controlled clinical trial.. Explore (NY), 2023. RCT
- [3]Effect of topical marshmallow (Althaea officinalis) on atopic dermatitis in children: A pilot double-blind active-controlled clinical trial of an in-silico-analyzed phytomedicine.. Phytother Res, 2021. pilot-RCT
- [4][Marshmallow Root Extract for the Treatment of Irritative Cough: Two Surveys on Users' View on Effectiveness and Tolerability].. Complement Med Res, 2018. observational
- [5]A randomized, open-label, multicenter, comparative study of therapeutic efficacy, safety and tolerability of BNO 1030 extract, containing marshmallow root, chamomile flowers, horsetail herb, walnut leaves, yarrow herb, oak bark, dandelion herb in the treatment of acute non-bacterial tonsillitis in children aged 6 to 18 years.. Am J Otolaryngol, 2019. open-label
- [6]Marshmallow.. Drugs and Lactation Database (LactMed®), 2006. database
What changed
- Initial editorial evidence review: every PMID checked against NCBI esummary (title, year, no retraction or expression-of-concern flag); doses, sample sizes and durations re-read against the PubMed abstract or open full text; grades kept conservative; interactions limited to what a cited source supports.
- Adversarial review: added the EMA's under-12 restriction for the stomach-discomfort tea to the children cautions.