Insulin shots are a regular part of the medication routine for people with diabetes. Those who have type 1 diabetes often have to take several insulin shots per day in order to maintain their blood glucose levels, while people with type 2 diabetes usually only take one or two shots per day.

Insulin

The main ingredient in an insulin shot is insulin. In most people, insulin is produced by beta cells inside the pancreas. People with diabetes have to take additional insulin via a shot because their bodies do not produce sufficient levels of the hormone.

Additives

Insulin shots contain additives. According to the American Diabetes Association, these additives "prevent bacteria from growing and help maintain a neutral balance between acids and bases."

Prolonged Reaction

An insulin shot that is intermediate or long-acting also contains additives to prolong its action throughout the day.

Strength Levels

The ingredients in an insulin shot vary according to its strength. For example, a shot with a strength of U-100 has 100 units of insulin per milliliter of fluid, while an insulin shot with a strength of U40 has 40 units of insulin per milliliter of fluid.

Speed

Insulin shots also vary by the speed at which they work. Each insulin shot varies according to its onset (how long it takes to reach the blood stream and start working), peaktime (the length of time it works at full strength to lower blood glucose levels), and duration (how long it continues to work). Each type of insulin shot contains slightly different ingredients to stretch out the duration of the insulin (American Diabetes Association).

Source:

American Diabetes Association: Insulin Basics

National Diabetes Information Clearinghouse: Types of Insulin