Other names:
Bruisewort, Knitbone, Boneset
What is it supposed to do?
Used topically to promote wound healing, bruises, sprains, broken bones
How it is supposed to work:
Mucilage and allantoin are considered the major constituents in comfrey
responsible for the herb’s anti-inflammatory actions
Toxic effects:
Comfrey leaves can cause liver toxicity. These toxic effects are most
likely due to the conversion of alkaloids via hepatic microsomal enzymes to
produce powerful alkylating agents.
The main liver injury caused by comfrey is obliteration of small hepatic
veins leading to cirrhosis and eventual liver failure.
Does it work?
No controlled studies have been conducted in humans because of its
substantial toxicity.
Other information:
It has been banned in many countries such as Germany and Canada.
References:
- Winship KA. Toxicity of comfrey. Adverse Drug React Toxicol Rev
1991; 10:47–59 [review].
