Insulin is a hormone that is produced naturally in our bodies. Its main role is to allow cells throughout the body to uptake glucose (sugar) and convert it into a form that can be used by these cells for energy. Naturally occurring human insulin is made by beta cells within the pancreas, but people with diabetes have little or no natural insulin release.
Insulin is mostly used to treat type 1 diabetes but can be used in people with type 2 diabetes if insulin levels remain low despite the use of other types of medications. Insulin may also be given to pregnant women who develop a type of diabetes during pregnancy called gestational diabetes.
Insulin is available as synthetic human insulin (made in a laboratory but resembles naturally occurring human insulin), insulin analogs (human insulin that has been genetically modified), and biosimilars. Insulin analogs are better than standard human insulin at mimicking natural insulin release. It is easier to predict how fast and how quickly they will be absorbed (taken up by the cells in the body) and how long they will last. Biosimilars can be used in place of brand name insulins and usually cost less.
Insulins are typically classified as rapid-acting, regular or short-acting, intermediate-acting, long-acting, and ultra-long acting. Combination insulins, that mix together different types, for example, rapid-acting insulin with intermediate-acting insulin, are also available.
