Examples

Rapid-acting

Short-acting

Intermediate-acting

Mixtures

Insulin normally is made by the pancreas, a gland behind the stomach. The medicine form of insulin helps the body use glucose. Insulin cannot be taken as a pill, because stomach acid destroys insulin before it can enter the blood.

Insulin is categorized according to how fast it starts to work and how long it continues to work. The types of insulin available include rapid-, short-, intermediate-, and long-acting insulin. See types of insulin for more information. Insulin strength is usually U-100, but U-500 is also available, which is five times more concentrated than U-100. If you are very resistant to insulin, U-500 allows you to inject fewer units but get more of the medicine.

Packaging

Insulin is packaged in small glass bottles that are sealed with rubber lids. One bottle of U-100 insulin holds 1,000 units, which is many doses of insulin. It is also packaged in small cartridges used in pen-shaped devices (insulin pens) attached to disposable needles. Insulin bottles and cartridges are labeled with important information you should read, such as the expiration date.

How insulin is taken

Insulin usually is given as a shot under the skin. It can also be given through an insulin pump or a jet injector, a device that sprays the medicine into the skin. Some insulins can be given in a vein, but this is only done in a hospital.

How It Works

Insulin reduces blood sugar levels by helping sugar (glucose) enter the cells to be used for energy. Sometimes women who have gestational diabetes need to take two types of insulin, usually a rapid- or short-acting and an intermediate-acting type. Long-acting insulins have not proved to be safe for use during pregnancy.

• The short-acting insulin reduces blood sugar levels quickly and then wears off.
• The combination of a rapid- or short-acting and intermediate-acting insulin helps keep blood sugar levels in a target range both before and after meals.