Injectable insulin is packaged in small glass vials (bottles) and cartridges that hold more than one dose and are sealed with rubber lids. The cartridges are used in pen-shaped devices called insulin pens.
How insulin is taken
Insulin usually is given as an injection into the tissues under the skin (subcutaneous). It can also be given through an insulin pump, an insulin pen, or jet injector, a device that sprays the medication into the skin. Some insulins can be given through a vein (only in a hospital).
Research is ongoing to develop new forms of insulin, as well as insulin that can be taken in other ways, such as by mouth or nasal spray.
How it works
Insulin lets sugar (glucose) in the blood enter cells, where it is used for energy. Without insulin, the blood sugar level rises above what is safe for the body.
Your body uses insulin in different ways. Sometimes you need insulin to work quickly to reduce blood sugar. Your body also needs insulin on a regular basis to keep your blood sugar within a normal or near normal range.
- Rapid-acting and short-acting insulins reduce blood sugar levels quickly and then wear off.
- When you use long-acting insulin with rapid- or short-acting insulins, the long-acting insulin starts taking effect when rapid- or short-acting insulins begin to wear off. The long-acting insulin glargine (Lantus) starts to work within an hour after it is given and continues to work at the same rate for about 24 hours. Lantus cannot be mixed in the same syringe with other types of insulin.
- Usually people who take insulin use a combination of a rapid- or short-acting and an intermediate- or long-acting insulin. This helps keep blood sugar levels within a range that is safe for the body throughout the day.
Why it is used
Insulin is used to treat:
- People with type 1 diabetes.
- People with type 2 diabetes whose pancreas produces little or no insulin or whose oral medications do not control their blood sugar. These people may take insulin either alone or along with oral medication.
- People with type 2 diabetes whose blood sugar levels are high because of a severe illness or major surgery. After blood sugar levels return to a target range, these people may be able to stop taking insulin.
- Women with type 2 diabetes who are pregnant or breast-feeding who cannot keep their blood sugar levels within a target range with diet and exercise. Only one oral diabetes medication (glyburide) has been studied for use during pregnancy. Until further research is done, the American Diabetes Association recommends that pregnant women and women who are breast-feeding not take oral diabetes medications.
Last Updated:
January 15, 2007
