Injecting Insulin

Insulin injections have considerably improved in recent years. Syringes and needles, which many people with diabetes were nervous about using, are now things of the past. Nowadays, insulin comes in the form of pens and cartridges with tiny disposable needles. They are much less painful than any other type of injection.

Injection sites

• You should inject your insulin under the skin in your stomach, thigh or buttocks. Insulin will have the quickest absorption rate injected into your stomach, a medium absorption rate injected into your thigh and the slowest absorption rate injected into your buttocks.
• Injecting insulin in the arm is no longer recommended as there is an increased risk of injecting it into the muscle rather than the tissue. If you inject insulin into muscle, it will be absorbed too fast.
• You should use different injection sites and not stick to the same one all the time. If you overuse the same site, fatty lumps can develop there. This is known as ‘lipohypertrophy’. If you inject your insulin into areas of lipohypertrophy, its action can be very unpredictable.

Before you inject insulin

• Double-check the name of the insulin and its expiry date.
• There is no need to disinfect the injection site.
• Screw the needle on to your insulin pen.
• Prime the needle – this means dialling two units and pressing the plunger until you see a drop of insulin at the tip of the needle.

How to inject insulin

• Insert the pen at a 90-degree angle to your skin and press the plunger all the way down.
• Hold the pen in place and count six seconds before removing it to ensure that you receive the full insulin dose.
• If you are using the correct length of needle you should not need to pinch up your skin to inject it. If you are very slim, however, you may need to use a shorter needle length. Your diabetes care team will advise you on this.
• Heat increases insulin absorption, so if you have just exercised, had a hot bath or gone to a sauna let your body cool down before you inject your insulin.

How to store insulin

• You should store your insulin in the fridge (at a temperature of 2–8º C).
• Once you start using a new insulin pen or cartridge it can remain at room temperature for four weeks (five weeks for Levemir). However, you should keep it away from direct sunlight or heat sources, such as a radiator.

The different types of insulin 

• Quick-acting insulins, which may be soluble or analogue. These are clear in appearance.
• Long-acting analogue insulins are also clear in appearance, so it is important to check the name on your insulin to make sure it is the correct type for you.
• Long-acting isophane insulins are cloudy. You need to mix these before you use them.
• Mixed insulins are a mixture of quick-acting and longer-acting insulins and come in various proportions.

Your insulin will be supplied either as cartridges to be loaded into reusable pens or as pre-filled disposable pen devices. Your diabetes care team will give you plenty of guidance and support with using whichever type of device you are prescribed.

Useful resources

For more detailed information on the different types of insulin, see Insulin.