Secretin
Secretin was the first hormone to be identified. In 1902, William Bayliss and Ernest Starling were studying how the nervous system controls the process of digestion. It was known that the pancreas secreted digestive juices in response to the passage of food (chyme) through the pyloric sphincter into the duodenum. They discovered (by cutting all the nerves to the pancreas in their experimental animals) that this process was not, in fact, governed by the nervous system. They determined that a substance secreted by the intestinal lining stimulates the pancreas after being transported via the bloodstream. They named this intestinal secretion "secretin". Secretin was the first such "chemical messenger" identified. This type of substance is now called a hormone, a term coined by Bayliss in 1905.
Testosterone benzoate
Testosterone benzoate, or testosterone 17β-benzoate, also known as androst-4-en-17β-ol-3-one 17β-benzoate, is a synthetic, injected anabolic–androgenic steroid (AAS) and an androgen ester – specifically, the benzoate C17β ester of testosterone – which was never marketed. It is a prodrug of testosterone and, when administered via intramuscular injection, is associated with a long-lasting depot effect and extended duration of action. The drug was first described in 1936 and was the first androgen ester and ester of testosterone to be synthesized.