Hormones are chemical messengers that instruct certain cells or tissues to act in a certain way that supports a particular function in the body.

it is essential for staying alive.

• speed of onset, or how quickly a person taking insulin can expect the effects to start.
• peak, or the speed at which the insulin reaches its greatest impact
• duration, or the time it takes for the insulin to wear off
• concentration, which in the United States is 100 units per milliliter (U100)
• the route of delivery, or whether the insulin requires injection under the skin,into a vein, or into the lungs by inhalation.

• Insulin is a vital hormone that controls how cells and tissues absorb energy as well as the breakdown of fats and proteins.

  Clusters of cells in the pancreas called islets secrete this hormone. When cells in the body respond less to its instructions, insulin resistance is increasing.

  In some people, the immune system attacks the islets, halting insulin production and leading to type 1 diabetes. Type 2 diabetes occurs when insulin resistance coexists with a lack of compensatory increase in insulin production.

  People can take insulin shots to counteract the effects of insulin resistance. There are fast, intermediate, and long-acting insulins that a person would take depending on how quickly they need to see a drop in blood sugar and the duration for which a person needs to control blood sugar.