Human testing is an important part of the clinical trial process to ensure drug safety. It involves 4 phases: testing on healthy volunteers, volunteers with the condition, determining safety and dosing, and final FDA approval testing. While it carries risks, laws and oversight aim to minimize harm, and human testing has led to important medical advances. However, it has also been abused, as in the Holocaust, leading to the Nuremberg Code of ethics to protect test subjects. Today, informed consent and oversight seek to prevent such abuses while allowing important research.