Comfrey Central - A Clearinghouse for Symphytum Information

Concluding Remarks

Comfrey has properties that suggest it may be a unique healing agent deserving further research. Studies to determine effective dose and therapeutic action are warranted. However, constituents in comfrey represent a health risk as well. In order to minimize the risk of liver damage in people using comfrey, more research is needed to obtain an accurate assessment of toxicity. Research to support the safe use of comfrey such as how to minimize plant production of PAs and determinations of metabolism pathways in humans would be invaluable.

Although not without merit, the comfrey research presented in the scientific literature has limited value in determining safety in humans for the following reasons:

Although a safe level of comfrey consumption is probable, the use of comfrey without apparent detrimental effects doesn't mean that liver damage is not occurring. Occult damage or undesirable subclinical effects is a characteristic of many medications including the over-the-counter medications such as acetaminophen (liver damage) and ibuprofen (gastrointestinal damage). However, in the case of these legal drugs, an assessment has been made and it was decided that possible benefit outweighed possible risk. Difficulties in using comfrey safely include:

2004 Dorena Rode       Acknowledgment