This chapter discusses the safety issues associated with herbal ingredients. A wide range of conventional policies controls the availability of herbal products to the general public. The accomplishment of this depends on their derivation and their categorization as medicinals, drugs, botanicals, or dietary supplements. Herbal remedies used as medicines may be traditionally or serendipitously derived, varying in formulation, preparation and standardization, sometimes unreliable as to plant identification or to chemical composition, and depending on their cultural source, infrequently validated in conventional ways, as to efficacy or safety. The detection of adulterated or contaminated herbal products is not easy, because many policies prevent these events to be fully implemented and ways to identify the problems are not easy to achieve. The potential danger of using certain botanicals or their compounds is recognized. Use of herbal remedies by pregnant or nursing mothers can result in the transmission of certain phytochemicals to the fetus or infant. The capacity of children to absorb, distribute, metabolize, and excrete certain substances differs from that of adults. Herbal effects on absorption can also affect the bioavailability of antibiotics.