A significant proportion of herbal medicine side-effects reported in the literature are related to the use of incorrect plants or products adulterated with pharmaceuticals agents or heavy metals.
The most extensive database of adverse effects from herbal therapies is held by the Uppsala Monitoring Center (UMC) the coordinating center for the WHO International drug monitoring program.
Their role is to identify drugs with problematic side effects and to maintain a single global database for drug safety data. The data comes from National centers in 72 countries and includes reports on traditional and herbal remedies.
These comprise a relatively small component of the database with 11.716 reports compiled over 20 years compared with more than 3 million records on orthodox medicine.
Debbie Shaw, Researcher Medical Toxicology Unit, St Thomas hospital trust, London, UK.