Plants toxic to livestock species have a significantly negative impact on agriculture but can be an important source of bioactive molecules for use in medicine. The initial research on plant toxicity is focused on the response to the poisoning and the specific livestock species impacted by the toxic plant. This research emphasizes the identification of the plant and natural product(s) responsible for the toxicity to livestock, the prevention of further poisonings, and the development of treatments for the affected animals. Once the bioactive molecules impacting the livestock species have been identified, research on these compounds is then focused on determining the mechanism of action, the development of models for further study, and the identification of potential drug candidates for the treatment of disease. Specific examples of the agricultural-based research that are relevant to Human and Veterinary Medicine include: cyclopamine from Veratrum californicum (western false hellebore), piperidine alkaloids from Lupinus species (lupines), and cicutoxin from Cicuta species (water hemlock).