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.
Estetrol (medication)
Estetrol was discovered in 1965 by Egon Diczfalusy and coworkers at the Karolinska Institute in Stockholm, Sweden, via isolation from the urine of pregnant women. Basic research on estetrol was conducted from 1965 to 1984. It was established that estetrol is exclusively synthesized in the fetal liver and hence that it is a fetal estrogen. By 1984, estetrol was regarded as a weak estrogen; interest fell, and research was virtually abandoned. Subsequently a project at Pantarhei Bioscience was started to investigate estetrol with state-of-the-art technologies in 2001, with the sole reasoning that estetrol must have some biological role or function of importance as it would not be produced in such high quantities in the fetus otherwise. By 2008, estetrol was of major interest for potential clinical use, and development was in-progress. As of 2018, it is in mid- to late-stage clinical development for a variety of indications.https://adisinsight.springer.com/drugs/800034634 It was initially developed by Pantarhei Bioscience and Estetra SA (subsequently renamed Estetra SPRL), and is now being developed by Mithra Pharmaceuticals.