Many people with diabetes take insulin to control their blood sugar (glucose). Insulin cannot be taken by mouth because it would be destroyed by digestion. Instead, most people who need insulin take insulin shots. Other ways to take insulin include insulin pens, insulin jet injectors, and insulin pumps. Someday people with diabetes may no longer need needles or shots to take insulin; researchers are testing news ways to get insulin into the bloodstream.

»	Background Information about Insulin
»	Types of Insulin
»	Other Resources for Insulin

»	Types of Insulin Delivery Devices
»	Insulin Delivery Devices Under Development
»	Other Resources for Insulin Delivery Devices

When we eat, our bodies break food down into organic compounds, one of which is glucose.

The cells of our bodies use glucose as a source of energy for movement, growth, repair, and other functions. But before the cells can use glucose, it must move from the bloodstream into the individual cells. This process requires insulin.

Insulin is produced by the beta cells in the islets of Langerhans in the pancreas. When glucose enters our blood, the pancreas should automatically produce the right amount of insulin to move glucose into our cells. People with type 1 diabetes produce no insulin. People with type 2 diabetes do not always produce enough insulin.

There are more than 20 types of insulin products available in four basic forms, each with a different time of onset and duration of action. The decision as to which insulin to choose is based on an individual's lifestyle, a physician's preference and experience, and the person's blood sugar levels. Among the criteria considered in choosing insulin are:

• how soon it starts working (onset)

• when it works the hardest (peak time)

• how long it lasts in the body (duration)

The insulin products used by people with diabetes are either taken from animals (pigs or cows) or manufactured in labs to be identical to human insulin. Beef insulin is no longer available in the United States. Beginning in January 2006, pork insulin for human use will no longer be manufactured or marketed in the U.S.

All insulin delivery devices inject insulin through the skin and into the fatty tissue below.

Most people inject the insulin with a syringe that delivers insulin just under the skin. Others use insulin pens, jet injectors, or insulin pumps. Several new approaches for taking insulin are under development.

Syringes
Syringes are hypodermic needles attached to hollow barrels that people with diabetes use to inject insulin. Insulin syringes are small with very sharp points. Most have a special coating to help the needles enter the skin as painlessly as possible. Insulin syringes come in several different sizes to match insulin strength and dosage.

Insulin Pens
Insulin pens look like pens with cartridges - but the cartridges are filled with insulin rather than ink. They can be used instead of needles for giving insulin injections. Some pens use replaceable cartridges of insulin; other models are totally disposable after the pre-filled cartridge is empty. A fine short needle, like the needle on an insulin syringe, is on the tip of the pen. Users turn a dial to select the desired dose of insulin and press a plunger on the end to deliver the insulin just under the skin.

Jet Injectors
Insulin jet injectors may be an option for people who do not want to use needles. These devices use high pressure air to send a find spray of insulin through the skin. Jet injectors have no needles.

Insulin Pumps
Insulin pumps are small pumping devices worn outside of your body. They connect by flexible tubing to a catheter that is located under the skin of your abdomen. You program the pump to dispense the necessary amount of insulin. Usually, you set the pump to give a steady small dose of insulin, but you can give an additional amount in a short time if needed, such as after a meal. If adjusted properly, these pumps allow close control of your insulin levels without multiple injections. You should not use this type of pump during physical activities that may damage the pump or disrupt the pump's connection to the body. You still need to monitor your blood glucose levels regularly if you use this type of device.

Researchers are now developing several new methods for delivering insulin. These include the insulin patch and inhaled insulin. The insulin patch, when placed on the skin, will give a continuous, low dose of insulin. To adjust insulin doses before meals, users will pull off the tab on the patch to release insulin. Inhaled insulin delivery systems will give insulin as a dry power, inhaled through the mouth directly into the lungs where it passes into the bloodstream. This aerosol delivery system will likely be about the size of a flashlight and use rapid-acting insulin.