Marshmallow: From an Emperor's Garden Decree to a European Classic

As early as the 8th century, Charlemagne decreed that it be grown in the gardens of his empire, and its name still lives on today in a world-famous confection: marshmallow is one of the most tradition-rich plants in European herbal knowledge – and its sticky roots have more to offer than sweetness alone.

A steppe plant conquers Europe's gardens

True marshmallow (Althaea officinalis) is a member of the mallow family that can grow up to 1.5 metres tall. Its upright, hollow stem and greyish-green, lobed leaves are covered in a soft, velvety down, and from July to September the plant produces large, pale pink flowers with purple-red anthers. The plant originally came from the steppe zones of southeastern Europe and western Asia, from where it spread to the Mediterranean and further into Central Europe. In the wild, it favours damp, occasionally slightly saline habitats such as riverbanks, ditches and coastal meadows – habitats that have become increasingly rare in parts of Europe, which is why marshmallow today comes mostly from controlled cultivation.

The plant was already described by the ancient scholars Dioscorides and Pliny, and its Latin byname "bismalva" or "dialthaea" translates roughly as "twice as effective as other mallows" – a sign of how highly its mucilage was valued even then. Folk names such as "cough root" or "slime root" tell the same story. The root was originally eaten as a vegetable; mixed with whipped egg white and sugar, its sticky components gave rise to the forerunner of today's marshmallow confection – a name that still echoes the plant, even though modern marshmallow sweets no longer contain any of it.

Mucilage: the substance behind it all

Marshmallow's traditional uses centre on its mucilage – complex, water-binding carbohydrate compounds found mainly in the root, but also in the leaves and flowers.

Plant part	Mucilage content	Key constituents
Root	up to 15–20%	galacturonorhamnans, arabinogalactans, glucans, rhamnogalacturonans, plus pectins, starch, natural sugars
Leaves	up to 10%	mucilage, flavonoids, essential oil
Flowers	lower than root	mucilage, flavonoids

How the mucilage layer settles over an irritated throat

For the mouth and throat, marshmallow is perhaps the plant's best-known application: traditionally, and according to the monographs of the European Medicines Agency (EMA) as well as the former German Commission E, marshmallow root is used for irritation of the oral and pharyngeal mucosa and for dry, irritant cough. Its mucilage forms a thin, protective film over the irritated area and briefly shields it from further irritation – a purely physical-mechanical principle that makes the plant a staple ingredient in classic chest and cough tea blends, often combined with other mucilage-rich herbs such as plantain or mallow.

A narrative review published in 2020, which systematically summarised animal and clinical data on Althaea officinalis, confirmed a cough-suppressing effect for dry cough – although combinations of marshmallow with other plant extracts have in practice been studied more thoroughly than marshmallow monotherapy alone. Two cell-culture studies from a German research group add a mechanistic layer: an aqueous root extract protected human macrophages in the lab from oxidative stress and dampened the release of pro-inflammatory messengers; a follow-up study observed comparable anti-inflammatory and cell-protective effects in endothelial cells, which also became more mobile – a hint at possible regeneration-supporting mechanisms. Both studies were conducted in cell-culture models (in vitro); whether these effects occur to the same extent in the human body is not yet conclusively established.

What laboratory studies observe about the skin

Beyond the throat, marshmallow has a long, largely experience-based tradition of external use: compresses, baths and poultices made from the root or leaves have traditionally been applied to dry, irritated skin and skin inflammation – an application that is not officially recognised by European medicines authorities but has begun to receive more targeted research in recent years.

At the molecular level, a research group at the University of Münster found that an aqueous marshmallow root extract inhibits the activity of the enzyme human hyaluronidase-1 and reduces its formation in skin cells (keratinocytes) in the lab. This enzyme breaks down hyaluronic acid, which in turn plays an important role in skin moisture retention and regeneration – again, a finding from cell-culture experiments rather than from use in humans.

A step further came from a randomised, double-blind clinical trial published in 2021 involving 40 children with moderate to severe atopic eczema: one side of the body was treated with a steroid-containing preparation, the other with a topical marshmallow flower extract or a placebo as a control. After four weeks, skin condition (measured by the SCORAD score) had improved to a comparable degree on both treated sides. This is a single, small trial in children – larger studies across different populations are still needed before broader conclusions can be drawn.

Preparation: why the cold infusion makes the difference

To extract as much of the root's mucilage as possible, marshmallow root tea is traditionally prepared not with boiling water like ordinary herbal tea, but with cold water. Hot water causes the starch in the root to swell, which hinders mucilage extraction.

Step	Method
Amount	1–2 teaspoons of dried, cut marshmallow root per cup
Steeping	pour over approx. 150–250 ml of cold water
Steeping time	1–2 hours, stirring occasionally
Finishing	strain, then warm to drinking temperature

Safety & use

Anyone with a known allergy to mallow-family plants should avoid marshmallow preparations. There is insufficient safety data for pregnancy and breastfeeding, so it is advisable to consult a doctor or pharmacist beforehand during this time. For children, the appropriate preparation and amount depends on age; here too, it is advisable to check with a doctor or pharmacist first, especially for younger children. Because marshmallow root contains natural sugars, this may be relevant for people with diabetes. Since the protective mucilage film can, in principle, also slow the absorption of other orally taken medications, it is advisable to leave a gap of roughly one to two hours before or after taking other preparations. No side effects are currently known.

Conclusion: tradition-rich, but still incompletely researched

Marshmallow's mucosa-protecting effect on irritant cough and throat discomfort is one of the longest-documented applications in European herbal knowledge and is mechanistically supported by current cell-culture data. For the skin, the first small clinical trial in children with atopic eczema offers an interesting, though still preliminary, signal. Larger, independent clinical trials – particularly on marshmallow monotherapy for cough and on external skin use in adults – are still needed to place traditional experience on a broader scientific footing.

---

This article is intended for general information about true marshmallow and does not replace medical advice, diagnosis, or treatment. If you have health concerns, please consult a doctor or pharmacist.

---