OTTAWA - Health Canada is advising Canadian consumers not to use or to ingest the herb comfrey or any health products that contain comfrey because they might contain a compound called echimidine, which may cause liver damage. As a precaution, consumers are advised not to topically apply comfrey-containing products to broken skin. This advisory applies to both approved and unapproved products. The comfrey herb is found in herbal and homeopathic preparations, and is marketed to treat digestive problems, lung problems, arthritis, ulcers, bruises, wounds, and sprains/fractures. Comfrey is also found in lip balms, burn salves, diaper rash ointments and other therapeutic skin care products.

There are several different species of comfrey, two of which are already prohibited from being used in therapeutic products in Canada because they contain echimidine. These species are prickly comfrey (Symphytum asperum) and Russian comfrey (Symphytum x uplandicum). While not all comfrey products contain echimidine, some comfrey products do not always identify the species of comfrey in the product. Therefore, consumers are advised to avoid all products containing comfrey.

Consumers are advised to check the labels of their herbal and therapeutic skin care products for the presence of comfrey or echimidine, and not to use any product whose labels list these ingredients.

What are the risks associated with comfrey use?

There have been several International reports associating the ingestion of comfrey (teas, capsules, leaves) with liver damage. No cases of liver toxicity related to comfrey have been reported in Canada.

What is Health Canada doing about this issue?

Health Canada has reviewed recent national and international research, as well as several reports associating the ingestion of comfrey (teas, capsules, leaves) with liver toxicity. Other international regulatory agencies, such as the US Food and Drug Administration, have taken steps to address liver-related risks.

Health Canada is conducting a market review to determine which health products on the Canadian market contain comfrey, echimidine or the two prohibited comfrey species (prickly and Russian). The department is issuing letters to manufacturers of approved health products that contain comfrey - those with Drug Identification Numbers (DINs) on the label - requesting that they submit evidence that demonstrates their products do not contain echimidine or the two prohibited comfrey species. Manufacturers, importers and distributors of unapproved products - those without DINs on the label - are required to remove these products from the Canadian market immediately. This does not apply to cosmetic products.

Health Canada will keep Canadians informed on any developments related to this issue, and when the review is complete, will take further action as appropriate to protect the health and safety of Canadians. As a precaution, until Health Canada's market review is complete, consumers are advised to avoid all products containing comfrey.

The same advice applies to comfrey use in animals; however, there are no authorized products that contain comfrey for veterinary use in Canada.

Comfrey may be identified by the following names:

• Ass Ear
• Black Root
• Blackwort
• Boneset**
• Bruisewort
• Consolida
• Consound
• Gum Plant
• Healing Herb
• Knitback
• Knitbone
• Salsify
• Slippery root
• Wallwort

**"Boneset" is also used as a synonym for 'Eupatorium perfoliatum,' which is not a comfrey species, and consumers are advised to call the manufacturer of any product labeled as containing "Boneset" to confirm the active ingredient. Consumers should consult with their health care professional if they have experienced any of the following symptoms after taking or applying the herb comfrey or products containing comfrey:

• nausea
• vomiting
• unusual tiredness
• weakness
• loss of appetite
• stomach or abdominal pain
• abdominal swelling
• appearance of blue spider veins on the abdomen
• swelling of the legs/feet
• diarrhea
• jaundice (yellowing of the skin or whites of the eyes)
• brown urine

Consumers are advised to consult with a health care professional (either conventional or complementary/alternative) about suitable alternate therapies they may use to replace comfrey. Consumers and health care professionals may report adverse reactions toll-free to Health Canada by telephone (866) 234-2345 or fax (866) 678-6789.