Iceland moss (Cetraria islandica) is a lichen (a moss-like plant) that grows on the ground in mountains, forests, and arctic areas. In addition to Iceland, the lichen is found in Scandinavia, Great Britain, North America, Russia, and other areas in the Northern Hemisphere. Iceland moss also grows in Antarctica.
The plant’s thallus (shoot) curls from 1–4 in (2.5–10 cm) tall. The dried thallus is used as an herbal remedy. Iceland moss is also known as Iceland lichen, cetraria, fucus, muscus, and eryrngo-leaved (spiny-leaf) liverwort.
Iceland moss is rich in calcium, iodine, potassium, phosphorous, and vitamins. The lichen is a bitter-tasting plant that is said to smell like seaweed when it is wet. Despite these unappetizing characteristics, Iceland moss has long been used in Scandinavia and Europe as a food source and a remedy for numerous conditions.
Historic uses of Iceland moss
People in countries including Iceland, Sweden, Norway, Finland, and Russia have used Iceland moss for food and medicine. When used for nourishment, the Iceland moss was ground into flour, which was used to bake bread. Boiling the plant was said to remove the bitter taste, so the plant was boiled and made into a jelly. The lichen became part of a gelled dessert with ingredients that could include chocolate, almonds, or lemon.
In addition, Iceland moss was boiled in milk, a beverage served as a remedy for such conditions as malnutrition. The milk-and-lichen beverage was served to sick people, frail children, and the aged. It was also used for serious conditions when the person was vomiting.
Iceland moss also had numerous folk medicine uses. The lichen was a folk remedy for tuberculosis, lung disease, chest ailments, and problems with the kidney and bladder. Iceland moss was also used to treat wounds that did not heal, diarrhea, problems with lactation, fevers, and gastritis.
Furthermore, people in Norway ate Iceland moss during a seven-year famine that started in 1807. The Russians found another use for the lichen during World War II, when they prepared a version of molasses with Iceland moss.
Contemporary uses of Iceland moss
The acids in Iceland moss have an antibiotic effect. It is a mild antimicrobial and a demulcent—a remedy that soothes irritated or inflamed mucous membranes. The lichen is used to treat inflammation of the mouth and pharynx, and for treatment of the common cold, fever, dry cough, and bronchitis. It is also used for people who have a tendency toward infection. Furthermore, the bitter herb is a remedy for digestive complaints, loss of appetite, and gastroenteritis. Iceland moss boiled in milk is still used as a tonic beverage for people recovering from illnesses. In addition, the lichen has been used to treat diabetes.
In Europe, Iceland moss cough drops are sold in pharmacies. The lichen is also sold in other forms for a range of conditions. In the United States, Iceland moss is generally found in powdered form and is usually consumed as a tea. It can also be used as a gargle to soothe a sore throat.
Iceland moss tea is made by pouring 1 cup of boiling water over 1–2 tsp of powdered Iceland moss. The mixture is covered and steeped for 10–15 minutes. Sweetener can be added to the tea, or the herb can be mixed with cocoa or chocolate. The average daily dosage of Iceland moss is 1–3 tsp.
An Iceland moss decoction can be made by putting 2 tsp of shredded lichen in 2 cups of cold water. The mixture is simmered for 10 minutes. It is then strained to squeeze out the juice. One cup of the decoction is consumed in the morning and another at night. Iceland moss can also be taken as a tincture.
In addition, Iceland moss can be used topically for skin rashes and fungus.
Iceland moss is safe when taken in proper dosages. However, Iceland moss is not regulated by the FDA. Before beginning herbal treatment, people should consult a physician, health practitioner, or herbalist to discuss potential cautions.
Powdered Iceland moss must be soaked in lye for 24 hours or filtered through ash in order to properly extract the lichen acids. One study found that poorly prepared Iceland moss may contain toxic levels of lead. A person should talk to an experienced herbalist or other health practitioner to determine a proper source for Iceland moss, and should not attempt to prepare it themselves.
In rare cases, external use of Iceland moss has caused sensitivity reactions.
Side effects include the rare sensitivity reaction, and the risk of lead poisoning in poorly prepared Iceland moss. In excessive doses or with prolonged use, Iceland moss may cause gastric irritation and liver problems.
There are no known interactions with standard pharmaceuticals associated with use of Iceland moss.