The discovery of medicines: drug testing on humans and the development of medical ethics before the 20th century

In this article, we review the historical approach to the discovery of medicines, human drug testing, and the development of medical ethics. We cover the period from prehistoric times until 1906, when the Pure Food and Drug Act was introduced in response to the poor quality of food products and medicines. In the first part of the article, we discuss the period before the 16th century when drug testing relied on observation, trial and error, prescriptions and recipes, and the first use of pharmacopoeias to ensure medication safety. The second part focuses on the 19th century which was marked, on the one hand, by pharmacological advancements and the rise of the pharmaceutical industry, and, on the other, by the need for the introduction of safety guidelines.