The field of toxicology — determining whether a product is safe or harmful — is evolving rapidly. Many innovative drug safety technologies based on human biology, rather than the biology of other animals, are available for assessing whether potential medicines are likely to be safe or toxic in humans. Unfortunately, many of these new methods have yet to influence the FDA’s decision-making, even though it has a program in place that could be adapted to include human-based methods for nonclinical assessment.