HERBS: Comfrey

Scientific name
Other names
Purported uses
Warnings
Adverse reactions
References

Comfrey

Scientific name

Symphytum officinale

Other names

Slippery root, knitbone, blackwort, bruisewort

Purported uses

NOTE: Comfrey has not been shown to be effective for any of the following conditions. Many cases of liver toxicity have been reported after comfrey use, and the Food and Drug Administration has advised that all comfrey products be removed from the market.

To treat bronchitis
To treat cancer�
To reduce inflammation in conditions such as rheumatoid arthritis
To treat peptic ulcers
To improve wound healing

Warnings

On July 6, 2001 the U.S. Food and Drug Administration, along with the Center for Food Safety and Applied Nutrition, advised all dietary supplement manufacturers to remove products containing comfrey from the market. Comfrey contains unsaturated pyrrolizidine alkaloids, which are hepatotoxic and hepatocarcinogenic.

Adverse reactions

Reported: Hepatotoxicity

References

1. Newall C, et al. Herbal Medicines: A Guide for Health-Care Professionals. London: Pharmaceutical Press; 1996.

2. Schulz V, et al. Rational Phytotherapy: A Physicians Guide to the Use of Herbs and Related Remedies, 3rd ed. Berlin (Germany): Springer; 1998.

3. Awang DVC. Comfrey. Can Pharm J 1987;120:101-4.

4. Tyler V. Herbs of Choice: The Therapeutic use of Phytomedicinals. Binghamton: Pharmaceutical Products Press; 1994.

5. Ridker PN, McDermott WV. Hepatotoxicity due to comfrey herb tea. Am J Med 1989;87:701.

6. Ridker PN, McDermott WV. Comfrey herb tea and hepatic veno-occlusive disease. Lancet 1989;1:657-8.

7. Ridker PM, et al. Hepatic veno-occlusive disease associated with the consumption of pyrrolizidine-containing dietary supplements. Gastroenterology 1985;88:1050-4.

8. Yeong ML, et al. Hepatic veno-occlusive disease associated with comfrey ingestion. J Gastroenterol Hepatol 1990;5:211-4.

9. Weston CFM, et al. Veno-occlusive disease of the liver secondary to ingestion of comfrey. Br Med J 1987;295:183.

10. Roitman JN. Comfrey and liver damage (letter). Lancet 1981;1:944.

11. Foster S, et al. Tyler’s Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies, 3rd ed. Binghamton: Haworth Herbal Press; 1993.

12. FDA advises dietary supplement manufacturers to remove products containing comfrey from the market [talk paper online] 2001 July 6 [cited 2001 July 11].