The history of endocrinology dates back to the dark ages when victors of battles ate their enemies’ organs, thinking they contained important powers— an antiquated version of hormone replacement. Perhaps one of the most notable historical displays of endocrinology was the practice of castration, which gained popularity in the 17centuries, to prevent puberty and preserve the soprano singing voices of young male singers. These men became known as the castrati.
A deeper understanding of endocrinology was gained in the late 19century with contributions by the following: Claude Bernard studied blood glucose levels and the communication among cells, tissues and organs; Charles Brown-Séquard injected himself with extracts of animal testicles and described the effects; and Josef Von Mering and Oskar Menkoski observed the effects of removing the pancreas from dogs.
Secretin was the first hormone to be described in 1902. Thereafter, further advances in science and experimentation in surgery, such as those by Harvey Cushing, led to the identification of many more hormones. In 1916 what is now known as the Endocrine Society was founded as the Association for the Study of Internal Secretions. In 1921, Frederick Banting and Charles Best discovered insulin when they reversed diabetes in dogs with pancreatic islet cell extract of healthy dogs. They later purified bovine insulin, with the help of James Collip and John Macleod, and used it to treat humans with diabetes. This revolutionized the treatment of diabetes worldwide. Read about their discoveries
Since then, the field of endocrinology, and especially diabetes, has continued to grow with the creation of new diabetes medications, the invention of the insulin pump, and advances in pancreas and islet-cell transplantation. Read more about the history of diabetes in the 200th anniversary article from NEJM.