Comfrey
Common name
Comfrey Root
ID
HD0020
Scientific name of the plant
Symphytum officinale L.
Anatomical part for use
leaf, root
Human use
Pain and inflammation
Summary
Symphytum officinale is a perennial flowering plant in the family Boraginaceae. Along with thirty four other species of Symphytum, it is known as comfrey. To differentiate it from other members of the genus Symphytum, this species is known as common comfrey or true comfrey. Other English names include Quaker comfrey, cultivated comfrey, boneset, knitbone, consound, and slippery-root. It is native to Europe, growing in damp, grassy places. It is locally frequent throughout Ireland and Britain on river banks and ditches. It occurs elsewhere, including North America, as an introduced species and sometimes a weed. The flowers are mostly visited by bumblebees. Internal or long-term topical use of comfrey is discouraged due to its strong potential to cause liver toxicity. (Source: Wiki)
Evidence Level
Level 4 (Individual reports repeated observed over 5 years among different countries)
Hepatotoxicity reports in literature
- Hepatic and pulmonary complications of herbal medicines : (Source)
- Hepatic veno-occlusive disease associated with comfrey ingestion : (Source)
- Comfrey herb tea-induced hepatic veno-occlusive disease : (Source)
- Veno-occlusive disease of the liver secondary to ingestion of comfrey : (Source)
- Hepatic venocclusive disease associated with the consumption of pyrrolizidine-containing dietary supplements : (Source)
Hepatotoxicity Description
Several cases of acute liver injury resembling sinusoidal obstruction syndrome (
SOS
) due to oral comfrey have been published. The injury usually arises within 1 to 2 months of starting the comfrey product (either extract in tablet form or large amounts of comfrey tea) with onset of right upper quadrant pain, nausea and weight gain (from fluid retention) followed by jaundice. Serum aminotransferase levels are usually only mildly elevated with a hepatocellular pattern of injury, although they may be markedly increased if tested during the early phases of the injury. Immunoallergic and autoimmune features are usually not present. The injury can be severe and rapidly lead to acute liver failure (acute sinusoidal obstruction syndrome), but more commonly presents insidiously with weight gain, ascites, weakness, and minimal serum aminotransferase elevations (subacute or chronic sinusoidal obstruction syndrome). (Source: LiverTox)
Traditional medicine
In folklore, Symphytum officinale roots were used in traditional medicine internally (as an herbal tea or tincture) or externally (as ointment, compresses, or alcoholic digestion) for treatment of various disorders, including commonly as a treatment for reducing the pain of osteoarthritis. Including John Gerard an English herbalist (1545–1612), mentions "the slimie substance of the roote made in a possett of ale" would help back pains. The leaves were also thought to be able to be eaten as a vegetable, similar to spinach.A 2013 review of clinical studies assessing the possible effect of comfrey on osteoarthritis found the research quality was too low to allow conclusions about its efficacy and safety. In Europe as of 2015, there were no comfrey products for oral use, and those for topical uses to treat bruises or joint pain were evaluated as having risk of liver toxicity. (Source: Wiki)
Common name
Comfrey Root
ID
HD0020
Scientific name of the plant
Symphytum officinale L.
Anatomical part for use
leaf, root
Human use
Pain and inflammation
Summary
Symphytum officinale is a perennial flowering plant in the family Boraginaceae. Along with thirty four other species of Symphytum, it is known as comfrey. To differentiate it from other members of the genus Symphytum, this species is known as common comfrey or true comfrey. Other English names include Quaker comfrey, cultivated comfrey, boneset, knitbone, consound, and slippery-root. It is native to Europe, growing in damp, grassy places. It is locally frequent throughout Ireland and Britain on river banks and ditches. It occurs elsewhere, including North America, as an introduced species and sometimes a weed. The flowers are mostly visited by bumblebees. Internal or long-term topical use of comfrey is discouraged due to its strong potential to cause liver toxicity. (Source: Wiki)
Evidence Level
Level 4 (Individual reports repeated observed over 5 years among different countries)
Hepatotoxicity reports in literature
- Hepatic and pulmonary complications of herbal medicines : (Source)
- Hepatic veno-occlusive disease associated with comfrey ingestion : (Source)
- Comfrey herb tea-induced hepatic veno-occlusive disease : (Source)
- Veno-occlusive disease of the liver secondary to ingestion of comfrey : (Source)
- Hepatic venocclusive disease associated with the consumption of pyrrolizidine-containing dietary supplements : (Source)
Hepatotoxicity Description
Several cases of acute liver injury resembling sinusoidal obstruction syndrome ( SOS ) due to oral comfrey have been published. The injury usually arises within 1 to 2 months of starting the comfrey product (either extract in tablet form or large amounts of comfrey tea) with onset of right upper quadrant pain, nausea and weight gain (from fluid retention) followed by jaundice. Serum aminotransferase levels are usually only mildly elevated with a hepatocellular pattern of injury, although they may be markedly increased if tested during the early phases of the injury. Immunoallergic and autoimmune features are usually not present. The injury can be severe and rapidly lead to acute liver failure (acute sinusoidal obstruction syndrome), but more commonly presents insidiously with weight gain, ascites, weakness, and minimal serum aminotransferase elevations (subacute or chronic sinusoidal obstruction syndrome). (Source: LiverTox)
Traditional medicine
In folklore, Symphytum officinale roots were used in traditional medicine internally (as an herbal tea or tincture) or externally (as ointment, compresses, or alcoholic digestion) for treatment of various disorders, including commonly as a treatment for reducing the pain of osteoarthritis. Including John Gerard an English herbalist (1545–1612), mentions "the slimie substance of the roote made in a possett of ale" would help back pains. The leaves were also thought to be able to be eaten as a vegetable, similar to spinach.A 2013 review of clinical studies assessing the possible effect of comfrey on osteoarthritis found the research quality was too low to allow conclusions about its efficacy and safety. In Europe as of 2015, there were no comfrey products for oral use, and those for topical uses to treat bruises or joint pain were evaluated as having risk of liver toxicity. (Source: Wiki)