Products which meet new official standards will be adorned with a leaf and the letters THR denoting they are on the Traditional Herbal Registry.
The scheme, run by the Medicines and Healthcare products Regulatory Agency (MHRA), goes live on May 1. Herbal medicines will also have to be sold with an information leaflet giving advice on subjects including how to take it and possible side effects. The scheme has been instigated to meet the demands of a 2004 European directive to make herbal and traditional Chinese medicines safer.
While nine in 10 people believe such medicines are safe, some have dangerous levels of heavy metals, while others contain toxic plant extracts or banned pharmaceutical substances. n one case, more than 100 people in Belgium suffered kidney failure and 18 developed cancer after taking a Chinese medicine in which the plant Aristolochia fangchi had been substituted for another. Others have been found to contain dangerous heavy metal compounds like arsenic chloride - often called 'realgar' on the label, and mercuric chloride - called 'calomel'.
Richard Woodfield, head of herbal medicine policy at the MHRA, said the new measures were necessary because many people were "under a misapprehension that all herbal medicines are safe".