[Info] A Warning about Butterbur

[epileric]

A recent alert:

The MHRA has recently become aware that unlicensed herbal products containing butterbur (Petasites hybridus) are being marketed in the UK and is warning consumers about the risks associated with the use of these products. Butterbur contains pyrrolizidine alkaloids (PAs) which studies have shown can result in serious liver damage and organ failure. PAs have also been shown to lead to cancer in animals. Butterbur is most commonly used to treat migraine and hayfever.

Butterbur products have been associated with cases of liver toxicity; 40 cases have been reported in the literature. Of these cases, nine were of acute hepatitis and two of the nine cases resulted in liver failure requiring transplantation. The cases of liver toxicity appear to have occurred with extracts of butterbur where the PAs had been removed and only small amounts remained. There is some evidence that other constituents found in butterbur such as the sesquiterpene constituents for example petasin may be implicated in the liver toxicity.

http://www.mhra.gov.uk/Safetyinformation/Generalsafetyinformationandadvice/Herbalmedicines/Herbalsafetyupdates/Allherbalsafetyupdates/CON140849