Insulin Pork is Insulin isolated from pig pancreas. Insulin is a hormone secreted by the beta cells of the pancreas to help move glucose from the blood into body cells for energy. People with Type 1 diabetes lose the ability to produce insulin and must inject it. In the past, all commercially available insulin came from the pancreases of cows or pigs. Pork and beef insulins are similar to human insulin, differing only in one or a few amino acids. However, even a slight difference is enough to elicit an allergic response in some people. To overcome this problem, researchers looked for ways to make insulin that would more closely resemble human insulin.