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.
Clearblue
In 1989, Clearblue released the first one-step home ovulation test, enabling women to measure their surge in Luteinising Hormone (LH) to determine their most fertile days. In 1999, the brand launched the world’s first dual-hormone fertility monitor, which allowed women to measure estrone3-glucuronide (estrogen) in combination with LH. The company created the first digital ovulation test in 2004. In 2013, the company also began offering an ovulation test with a dual hormone read detecting both estrogen and LH.