Patient safety is of paramount importance for any drug discovery program.  This course looks at some of the lessons learned which have influenced how promising molecules are currently evaluated for safety risks.  In vitro and in vivo toxicology and safety studies are discussed, why they are performed, and how the data they provide guide a safety risk assessment, including determining a therapeutic index or safety window for a drug.  Finally, the course will look at how safety data guide human dose selection, and some of the studies performed during clinical development. Target audience: This course is suitable for life scientists, clinicians, and individuals from fields that support drug discovery (e.g., patents, finance, licensing, etc.) interested in learning more about the pharmaceutical/biotechnology sector. Advanced undergraduate coursework or practical familiarity/working knowledge in biological sciences and organic chemistry is recommended.