Insulin

What insulin does

Insulin is a hormone made by the pancreas. It helps sugar from the food you eat move out of your blood and into your body's cells, where it is used for energy. In type 1 diabetes, the pancreas stops making insulin, so you take it instead.

Diabetes Canada's guidelines call insulin the life-sustaining therapy for type 1. Your team decides with you how many injections you need, when to take them, how much to take, and whether a pump suits you. There is no single plan that fits everyone.

Types of insulin

Insulins are grouped by how quickly they start working and how long they last. These times are rough guides, and each product is a little different. Your pharmacist or the leaflet in the box will tell you about yours.

Premixed insulins, which combine a fast and a slower insulin in one pen, also exist. Diabetes Canada's guidelines say they are not suitable for most adults with type 1, because type 1 needs frequent adjustments. Cloudy insulin needs gentle mixing before each use: roll it between your hands and tip it up and down, as your educator shows you.

Never stop your basal insulin

If you can't eat or can't keep food down, call your team about your mealtime insulin and any changes to your doses. See Sick days and Highs and ketones.

Carry a card in your wallet that says you have type 1 diabetes, or wear a medical ID bracelet or necklace. In an emergency it tells others that you need insulin.

Pens, syringes and pumps

• Pens come filled with insulin and are easy to carry. You put a new needle tip on for each injection, and you need a separate pen for each type of insulin. Never share a pen, even with a new needle.
• Syringes draw insulin from a small bottle (a vial). Today's syringes are small with thin needles, and they cost less than pens.
• Pumps are small devices worn on the body that give insulin all day and night through a thin tube under the skin. Many work with a continuous glucose monitor. See Insulin pumps.

Use each needle or pen tip once, then put it in a sharps container. Many pharmacies give out puncture-proof containers and take full ones back.

Where to inject, and rotating sites

Insulin is injected just under the skin. The common places are:

• Belly: easy to reach, and insulin is absorbed quickly and evenly there. Stay about 5 cm (three finger widths) away from your belly button.
• Buttocks and thighs: insulin is absorbed more slowly.
• Outer arm: after the belly, the next fastest. It is hard to reach on your own, so it is often not recommended.

Change where you inject each time. Using the same spot again and again can cause fatty lumps under the skin, and insulin works poorly when it goes into them. Switch sides of your belly, and move to a slightly different spot each time.

Wash your hands and make sure the skin is clean before you inject. Don't inject through clothing. Your nurse or educator will show you how to give an injection step by step, including priming a pen so the needle is not blocked.