Icelandic moss is a popular European folk medicine commonly used for colds, coughs, mouth irritation, and respiratory issues.

It’s also known as Eryngo-leaved Liverwort, Iceland Lichen, and Lichen d’Islande.

While some swear by its healing properties, critics argue there is little research to back up its claims and that consuming the moss may be harmful. This may have you wondering if you should try Icelandic moss.

This article tells you all you need to know about Icelandic moss, including its health claims, downsides, and risks.

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Icelandic moss (Cetraria islandica) isn’t moss. It’s actually a lichen.

A lichen is a dual organism consisting of a type of fungi and algae or bacterium. Both coexist together to allow it to exist in harsh climates (1, 2).

This symbiotic relationship keeps Icelandic moss well protected and nourished.

While fungi lack the plant pigment chlorophyll and can’t undergo photosynthesis, algae can undergo this process to provide nourishment, and the fungi provide protection from the environment (2, 3, 4).

Despite not being a moss, Icelandic moss gets its name from its moss-like appearance. Its color varies from yellowish green to dark greenish gray. It has a cartilaginous texture that grows well in various climates.

Interestingly, the growth of Icelandic moss and other lichens is a sign of a healthy ecosystem, as they can absorb nutrients and pollutants around them. Therefore, environments in which Icelandic moss grows are believed to indicate low pollution levels (3, 5).

That said, Icelandic moss can still be contaminated with pollutants and heavy metals that may pose concern for human consumption (5, 6).

For centuries, Icelandic moss has been used as a European folk medicine to treat various ailments such as colds, coughs, respiratory illness, and digestive issues.

It’s most commonly used as a lozenge or cough syrup but can also be consumed as a tea, ground in soups and porridge, as feed for reindeer, and as a flavoring for alcoholic beverages.

In the United States, it is only approved for use as a flavoring agent in alcoholic beverages (7).

Summary

Icelandic moss isn’t moss at all. It’s a type of lichen — fungi and algae combined — used in European folk medicine as a natural health remedy for colds, coughs, and other health issues.

Icelandic moss has been used in European folk medicine for centuries as a natural remedy for many health ailments. Though, there is little research to back up its purported benefits.

Cold and cough

Icelandic moss is most commonly used to alleviate colds, coughs, mouth irritation, and respiratory issues.

It’s usually taken as a lozenge but can also be consumed as a tea. While some older studies are available, no modern research trials exist.

In one study, 1,848 children 4–12 years of age with upper respiratory infections were given 4–6 Isla-Moos lozenges (80 mg Icelandic moss extract per lozenge) daily for 1–2 weeks (8).

By the end of the two weeks, 39% had fully recovered, and 55% had improved symptoms. However, because there was no control group, it’s unknown if the lozenges caused the improvements in symptoms (8).

Additionally, six children experienced adverse reactions such as itching, nausea, abdominal pain, heartburn, and burning inside the mouth, which the authors believe may be caused by the lozenges (8).

Another study in 61 patients postnasal surgery found 10 Isla-Moos lozenges (480 mg of Icelandic moss extract) led to significant reductions in mouth dryness and inflammation caused by breathing through the mouth. No adverse reactions were reported (9).

Icelandic moss is believed to relieve cold and cough symptoms due to its anti-inflammatory properties.

Two fibrous compounds, lichenan and isolichenan, are believed to activate interleukin 10 (IL-10), an anti-inflammatory cytokine, to support the immune system fight infection (10, 11).

However, more research is needed to support this theory.

Other claims

Icelandic moss is used in traditional medicine to treat other health issues, such as respiratory diseases, loss of appetite, indigestion, cuts, and wounds.

Despite its historical use, there is insufficient evidence to support using Icelandic moss in treating any of these conditions.

Summary

Icelandic moss is most widely known for its role in alleviating coughs, sore throat, and mouth irritation. Though available as a lozenge in many European countries, more research is needed.

Icelandic moss lozenges have had some reported side effects.

One study showed that consuming Isla-Moos lozenges (80 mg Icelandic moss extract per lozenge) for 2 weeks led to itching, nausea, abdominal pain, heartburn, and burning inside the mouth in less than 1% of participants (6 out of 1,848) (8).

There are no known drug interactions from taking Icelandic moss, but it does contain fibrous mucilage compounds (lichenan and isolichenan), which may decrease the absorption of medications and reduce their efficacy (12, 13, 14).

Further, because Icelandic moss absorbs pollutants, it may contain high amounts of lead and other heavy metals, though more data is needed.

Until then, consuming untreated Icelandic moss isn’t recommended (6, 14).

Summary

Side effects of taking Icelandic moss may include itching, nausea, abdominal pain, heartburn, and mouth irritation. It may also decrease the efficacy of certain medications, and untreated varieties may contain high levels of heavy metals.

Icelandic moss appears to be safe when taken as an extract in lozenges for children and adults with dry cough and sore throat, provided they follow the recommended dosage for no more than 1–2 weeks (14).

Though likely safe due to similar preparation techniques, no safety data is available for Icelandic moss syrup.

Due to lack of data, those who are pregnant, breastfeeding, or are on any medications should avoid taking Icelandic moss in all forms (14).

Summary

Icelandic moss appears safe when taken as a cough or cold lozenge. Those who are pregnant, breastfeeding, or are taking medications should avoid taking Icelandic moss due to lack of safety data.

Icelandic moss is a natural remedy for cold and cough relief in many European countries and is usually sold as a lozenge (Isla-Moss) or syrup.

It’s also available as an herbal tea or ground powder added to soups, porridge, and other dishes. Further, it’s sold as a homeopathic tincture in some countries at a ratio of 1-to-5 (Icelandic moss to 40% ethanol) or as a supplement (14).

However, it’s not permitted for sale in the United States besides as a flavoring agent for alcoholic drinks (7).

You can also purchase Icelandic moss skin care products such as soaps, scrubs, and creams, although little data exists on their efficacy.

It isn’t recommended to consume untreated Icelandic moss, as it may contain high levels of heavy metals (6, 14).

Due to a lack of scientific data, an appropriate dosage recommendation can’t be made.

However, because of the risk of potential side effects and drug interactions, it’s best to follow the directions on the label and speak with your healthcare professional before trying it.

Summary

Icelandic moss is most popular as a lozenge, but it’s also available as an herbal tea, powder, supplement, homeopathic tincture, and skin care product. Always follow the directions on the package and ask your healthcare professional before trying it.

Icelandic moss is a type of lichen that grows mostly in Iceland. It’s available as a lozenge, cough syrup, supplement, herbal tea, homeopathic tincture, and skin care ingredient.

Some research supports taking Icelandic moss lozenges to alleviate a sore throat, cough, and mouth irritation. However, more research is needed for its use in treating indigestion, cuts or wounds, loss of appetite, and other health issues.

Due to its ability to absorb environmental pollutants, it may contain high levels of heavy metals. Therefore, untreated Icelandic moss should be avoided.

Further, those who are pregnant, breastfeeding, or taking any medications should avoid it.

If you’re looking to try Icelandic moss, check to see if it’s available for sale in your country, and always speak with a healthcare professional before trying it.