What is Marshmallow?

Marshmallow is the root of Althaea officinalis, a tall plant of damp ground and old gardens. The dried root is made into teas, syrups, lozenges and capsules. It is used to soothe a dry, tickly throat and a dry cough.

The root holds a lot of mucilage. That is a slippery gel that forms when the root sits in water. The idea behind every traditional use is that this gel coats and calms sore surfaces.

It is not the same as the white candy. Modern marshmallows contain no plant at all. The leaf is also used, but the root is the stronger source of gel.

Here is the honest verdict. Tradition is long, wide and consistent, but human trials are few and weak. Traditional use is not proof that a remedy works, and it is not proof that it is safe.

How does Marshmallow work?

The proposed action is physical, not drug-like. The gel is thought to form a thin layer over the lining of the mouth and throat.

In laboratory tests, marshmallow mucilage sticks to cells grown from mucous membranes. Lab work also suggests it may calm irritated cells. Whether this happens in a real sore throat has not been shown well.

In animal studies, root extracts have reduced coughing. Animal work does not prove the same effect in people.

Some lab and animal studies point to a protective effect on the stomach lining. That has not been tested properly in humans.

One point follows from the gel itself. Because it coats the gut, it may slow how fast other swallowed medicines are taken up. That is a practical issue rather than a proven harm.

What forms does Marshmallow come in?

Common forms include:

Dried cut root, soaked in cold water to make a slippery infusion.

Root powder in capsules.

Syrups, often with other soothing herbs, sold for dry cough.

Lozenges and pastilles for throat comfort.

Tinctures, which are alcohol-based and carry little gel.

Dried leaf, used as a weaker tea.

Powder or crushed root used as a warm poultice on skin, in older folk practice.

Syrups and lozenges often contain sugar. That is worth checking if you watch your blood sugar or your teeth.

Where it comes from:

Marshmallow has one of the longest written records of any Western herb. Greek and Roman writers listed it as a food and a soothing remedy. Arabic and medieval European texts carried it forward.

American folk healers and the Eclectic physicians of the 1800s kept it in regular use. They classed it as a demulcent, meaning a coating, soothing agent. They gave it for coughs, raw throats, irritated bowels and burning on passing urine.

The old name mortification root came from wound care. Mortification meant tissue dying, and poultices of the root were packed onto angry wounds and swellings. That use is historical only and is not a model for home care today.

The folk name mallards is a regional corruption of mallow.

What does Marshmallow help with?

• Dry, tickly cough: This is the best supported use, though the support is modest. European regulators allow marshmallow root cough products on the strength of long use, not trial results. Small open studies of root syrups and lozenges reported less cough, but they had no placebo group. The effect, if real, is likely to be brief coating comfort rather than treatment of the cause.
• Sore or irritated throat: Tradition used it as a gargle and a slow-sipped tea. The gel does coat surfaces in lab tests, which fits what people report. There are no good trials of marshmallow alone for sore throat. It does not treat a bacterial infection.
• Dry mouth: Herbalists have used soaked root to relieve a dry mouth, including dryness from medicines. Human evidence is close to absent. Any relief is likely short and physical.
• Heartburn and reflux discomfort: American folk and Eclectic practice gave it for burning in the gullet. A few small trials of mixed herbal products that included marshmallow reported relief. Because other herbs were present, the credit cannot be given to marshmallow. It does not heal reflux damage or replace acid-lowering treatment.
• Irritated stomach lining: In animal studies, root extracts protected the stomach from damage. This has not been shown in people. Stomach pain needs a cause found, not a coating.
• Mild constipation: The root is bulky and holds water, so it has been used as a gentle bulking agent. Direct human evidence is lacking. Plenty of fluid matters with any bulk-forming agent.
• Irritated or chapped skin: Poultices and creams were used on sore, dry or inflamed skin. Some lab work suggests the mucilage helps hold moisture. Human trials of marshmallow alone on skin are scarce.

Which foods are rich in Marshmallow?

No everyday food is a meaningful source. The root was eaten in times of scarcity, and old confectionery once used the sap. Modern marshmallow sweets contain none of the plant.

What are the side effects of Marshmallow?

• Bloating or wind
• Loose stools
• Nausea with large amounts
• Reduced uptake of other swallowed medicines
• Low blood sugar, reported rarely and mainly in theory
• Allergic reaction, including rash, itching or swelling
• Choking if dry powder is swallowed without fluid

Good to know:

Side effects are uncommon and usually mild. Marshmallow is one of the gentler herbs in common use, and it has a long food history.

The gut effects come mostly from the bulk, not from a drug action. Allergy is rare but possible, as with any plant.

The most likely real-world problem is not harm from the herb. It is a medicine you need working less well because the gel slowed its uptake.

How much Marshmallow should you take?

• Recommended daily: This is what labels and herbal monographs typically carry, not advice for you. Tea or cold infusion: about 2 to 5 g of dried root per cup, taken a few times a day. Syrups and lozenges: dosed per the product label, which varies a lot by strength. European traditional-use products for adults usually fall near 5 to 15 g of dried root a day in total. Child doses are lower and are set by the product. A pharmacist or doctor should set the amount for a child.
• Best time of day: Time of day does not matter much. People often take it when the throat feels worst, which is frequently at night. The one timing rule that does matter is spacing it away from other medicines. See the interactions section.
• With or without food: Food makes little difference to how it works. Take it with plenty of water, especially the powder or capsules. Dry powder swallowed without fluid can stick and cause choking. Keep a gap of at least two hours between marshmallow and any other medicine you swallow.
• Time to effect: If it helps a throat, it tends to help within minutes, while the gel is in contact. The comfort fades as it is swallowed and washed away. That is why it is taken often rather than in one big dose. For stomach or bowel uses, any effect would be slower and is much less certain. It may do nothing at all.
• How long to take it: It is normally used in short courses, over a few days to about two weeks. A cough that lasts more than three weeks needs a doctor, not a longer course of syrup. The same goes for throat pain or heartburn that keeps coming back. Long daily use has not been studied, so nobody can say it is safe for months on end.