What does comfrey contain?
Comfrey is a good source of allantoin; allantoin facilitates the growth of new cells
including bones.

In general, comfrey is considered as a medicinal plant with anti-inflammatory, analgesic
and tissue regenerating properties in Germany. A clinical study shows its efficacy on
acute ankle sprains, pain and edema. [2] Topical application of comfrey shows
improvement of morning joint stiffness with good tolerability in another trial. [3]

What are the side effects of comfrey?
The side effects of oral-intake comfrey can be extremely serious. Comfrey is a rat liver
toxin and carcinogen. It tumorigenicity is related to its genotoxicity of pyrrolizidine
alkaloids in the plant. [1]

Pyrrolizidine alkaloids have been linked to substantial toxicity after their intake as tea
and in the setting of contaminated cereals have led to endemic outbreaks in Jamaica,
India and Afghanistan. Its leave is a substantial health hazard with hepatic toxicity.
The mechanisms are not fully understood but believed to be related to the
biotransformation of alkaloids. Comfrey causes veno-occlusive disease first, then
eventually liver failure. [4]

[1] Mei N et al, Mutagenicity of comfrey (Symphytum Officinale) in rat liver. Br J Cancer 2005 Mar
14;92(5):873-5. [2] Koll R et al, Efficacy and tolerance of comfrey root extract (Extr. Rad. Symphyti) in the
treatment of ankle distorsions: results of a multicenter, randomized, placebo-controlled, double-blind study.
Phytomedicine 2004 Sep;11(6):470-7. [3] Koll R., Therapeutic characteristance and tolerance of topical
comfrey prepartions. Results of an observational study of patients Forschr Med Org 2002;120(1):1-9. [4]
Stickel F et al, The efficacy and safety of comfrey Public Health Nutr 2000 Dec;3(4A):501-8.
WHAT IS COMFREY? What are the health benefits of comfrey? Comfrey [Symphytum officinale. L.] is a vigorous,
perennial garden plant of the borage family. Comfrey is a popular herb for burns, bites, cuts, strains, sprains and
broken bones.
Discuss with your doctor before taking any alternative medicine. This article is for
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