Questionable scientific studies were performed for centuries until ethics groups were formed to restrict the types of experiments that could be carried out on live subjects. Fortunately, the fields of biomedicine and psychology have improved greatly when it comes to the types of experiments that can be done on humans and the importance of consent.
Nonetheless, shocking human trials were still performed up until relatively recent history, and cruel experiments involving animals are still carried out to this day. Click through the gallery to learn about some of the most heinous and unethical science experiments of all time.