(Advanced) In the past several years there have been numerous adverse events associated with Chinese herbal medicines ranging from adulterations that may lead to kidney failure (Stephania, Clematis, Aristolochia) and birth defects ("Siberian ginseng"), or the presence of pharmaceutical drugs (acetaminophen) or other contaminants (heavy metals-bufo toxin) in classic Chinese formulas. This session will discuss the individual herbs and formulas shown to be problematic and provide insights for how to avoid such problems.