The Impact of Quality Issues on the Safety of Herbal Products

Probably the most commonly documented reason for toxic or adverse reactions to herbal products is the presence of adulterants. In this context the term "adulterants" can be defined as the intentional or unintentional presence of undeclared ingredients that impact adversely on the safety of the product. This adulteration may be caused by: • Unintentional or intentional substitution of one or more herbal ingredients with toxic species; • Intentional addition of a conventional chemical drug, either of natural or synthetic origin; • Environmental contamination of the herb with a chemical or pathogen; and • Intentional addition of a "natural" active component that is responsible for the adverse reaction, such as a microorganism, mineral, or nutrient. These problems can generally be overcome with responsible manufacture, adequate testing, and, above all, a commitment to pharmaceutical level good manufacturing practice (GMP).