A risk and benefit assessment are crucial to support the safe use of herbal products although the consumers perceive herbal product as “safe” and “natural” and thus “healthy”. The aim of the thesis was to perform an assessment of potential risks and some benefits of herbal products available on the Indonesian market. First, potential health risks due to the presence of genotoxic and carcinogenic compounds, including alkenylbenzenes, pyrrolizidine alkaloids (PAs) and aristolochic acids, in jamu and herbal beverages was assessed. Next, the applicability of a novel testing strategy, quantitative in vitro to in vivo extrapolation (QIVIVE) was used to investigate monocrotaline-induced acute liver toxicity in rats which can help to fill data gaps in the currently available data base on the toxicity of PAs. In addition, QIVIVE was applied to provide a proof of principle to predict potential beneficial effects of the botanical constituents bixin and crocetin in humans. Altogether the data show that natural does not always equal safe and that health claims related to botanicals may not always be in line with the scientific data.