What is insulin?
Why do people with type 1 diabetes need insulin?
How is insulin taken?
Types of insulin
Are there any side effects?
Storage of insulin
What is insulin?
Insulin is a hormone naturally produced in the body by the beta cells of the pancreas. Insulin allows glucose to enter the body's cells where it is used for energy. It also allows excess glucose to be stored in the liver for later use, such as overnight and between meals. A small amount of insulin is released from the pancreas into the bloodstream throughout the day and when food is eaten.
Insulin was first manufactured by scientists in 1922, and since then insulin therapy has been a revolutionary and lifesaving treatment for people with type 1 diabetes and is necessary to control blood glucose levels in many people with type 2 diabetes.
Originally insulin was extracted from the pancreas of pigs and cows, but is now manufactured by genetic engineering to be similar to human insulin. New insulins, called analogues, have been created which act more quickly or slowly in the body than regular insulin.
Type 2 diabetes is a progressive disease, so most people will need insulin eventually. Although people with type 2 diabetes do make their own insulin, over time the pancreas becomes exhausted and makes less and less insulin. This does not mean that they suddenly have type 1 diabetes.
Insulin cannot be taken by mouth as it is destroyed by the digestive chemicals in the stomach. Other forms of insulin therapy have been trialled, such as, inhaled or transdermal patch (through the skin) however, to date injections remains the most reliable, effective and inexpensive way of administering insulin. With modern technology, injecting insulin has become easier and almost painless with a greater choice of devices.
Insulin pens make injecting simpler and more convenient. Reusable insulin pens are used with 3ml insulin cartridges. Each cartridge contains 300 units of insulin. Insulin pens are made to fit specific brands of insulin. They are not interchangeable.
Disposable insulin pen devices are prefilled with 300 units of insulin and discarded when empty.
Pen needles can be used with any brand of pen and come in several different lengths to make injections as painless as possible.
|Reusable pens||Disposable pens||Insulin brand|
NovoPen 3 Demi
|Novo Nordisk insulins|
Sanofi Aventis Insulin
Insulin pumps are battery operated devices that deliver a continuous small dose of insulin with extra insulin given with meals. Pumps are not usually required for people with type 2 diabetes.
Ask your diabetes educator about the injection device that is best for you.
Needles and syringes are free for people registered with the National Diabetes Services Scheme (NDSS). A doctor or 'credentialed' diabetes educator can register you in this scheme. Contact us for more information on NDSS or for an NDSS registration form.
The number of injections required and the type and dose of insulin varies between individuals. Insulin should be tailored to your lifestyle and eating habits and will be decided on the basis of your blood glucose pattern throughout the day and before and after meals.
Insulin is very safe when used with the guidance of your health professional and at the correct dose. The main side effect is hypoglycaemia (low blood glucose level). Mild hypoglycaemia can be treated very quickly by the person with diabetes without too much disruption to their day. Very low blood glucose levels can be dangerous and must not be ignored. Find out more about hypoglycaemia.
Some people may experience a slight reaction where the injection was given. This usually goes away within a few days. Very rarely, a person may experience a reaction to the insulin that requires them to stop it and start another type of insulin. If you experience any side effects please inform your doctor.
Weight gain can occur after starting insulin therapy. Often, the longer people wait before starting insulin, the more weight they gain. This can be curbed by increasing exercise and reducing energy intake. The benefits of better blood glucose control with insulin outweigh the risks of increased weight.
Insulin is injected through the skin into the fatty tissue known as the subcutaneous layer. Fatty lumps can develop in places that are over-used for injecting insulin so it is important to inject in a different spot each day. Insulin does not work as effectively when injected into areas of lipohypertrophy.
If you do have lipohypertrophy, the lumps can go away if you avoid injecting in these areas for a while. However, discuss this with your health care team. Your insulin dose may need to be reduced as it may work better in a new site and cause hypoglycaemia.
Insulin can be injected into the following areas:
1. abdomen (tummy)
2. upper outer arms (not into muscle)
4. upper outer thighs
The abdomen is the preferred site as the absorption of insulin is more stable and most people have some fat under the skin here. You should avoid injecting into a muscle because it will be absorbed more quickly and could cause hypoglycaemia.
Unopened insulin should be stored in the fridge, between 2-8 degrees Celsius. Once opened, insulin may be kept at room temperature (between 25 to 30 degrees celsius) for one month and then discarded.
Insulin can be damaged by extreme temperatures. It must not be left where temperatures reach over 30 degrees, eg, in the car or in direct sunlight.
Insulin should not be allowed to freeze as it will lose its potency, and must be discarded.
Find out more about storage of insulin when travelling or camping.
Discard insulin when
- Clear insulin has turned cloudy
- The expiry date has been reached
- The insulin has frozen or is exposed to high temperatures
- Lumps or flakes are seen in the insulin
- Deposits of insulin are seen on the inside of the vial and cannot be dissolved by gently rotating the vial
- The vial has been open for longer than one month (regardless of whether it has been in the fridge or expiry date has not been reached)
When you start insulin
People with diabetes need to learn to self manage their diabetes, and to do this well takes time, education and support. When you start insulin, you should have the help of a diabetes nurse educator who will teach you.
- How to inject insulin and how it works
- How to check your blood glucose levels (BGL)
- What to do if BGL are high or low
- How to recognise and treat a 'hypo' (low blood glucose)
- What to do when you are sick
- How to adjust insulin doses when you play sport or travel
- Where to get the equipment you need
- How to join the National Diabetes Services Scheme (NDSS)
Injecting insulin does not take long to get used to. In fact many people, once started, wonder why they put it off. Most people start feeling better very quickly and find insulin injections much easier to manage than expected.
Used syringes, pen needles and lancets must be disposed of in an Australian Safety Standards-approved sharps container which is puncture proof and has a secure lid. These are usually yellow in colour and are available through pharmacies, your local municipal council and DA–Vic.
People in many developing countries are unable to access insulin and strips,which affects their health and survival. If you have no longer needed, unopened and in-date (with at least three months to use-by date) insulin and test strips, please consider donating them to "Insulin for Life Inc." or at PO Box 2010 Ballarat Mail Centre, Vic 3354. These are then donated overseas following specific requests from recognised organisations and with an agreed protocol.