Insulin is used to treat diabetes. Find out how to take it safely and possible side effects.
On this page you will find information on:
Types of insulin
There are different brands of insulin available in New Zealand and these are grouped by the time it takes for the insulin to work.
|Type of insulin
- Usually works straight away, so it is injected just before or with food.
- Its effect lasts 1–2 hours.
- Examples: NovoRapid, Apidra, Apidra Solostar, Humalog
- Usually works within 15–20 minutes, so inject each dose 15–20 minutes before you eat.
- Its effect lasts 3–4 hours.
- Examples: Actrapid, Humulin R
|Intermediate and long-acting insulin
- Usually works after about 1 hour.
- Its effect lasts all day and may be injected once or twice a day.
- Examples: Protophane, Humulin NPH, Lantus, Lantus Solostar
- These insulins are a mixture of short and intermediate-acting insulins.
- These may be injected 2 or 3 times a day, in the morning, before breakfast and before dinner. Premixed insulin must be injected before dinner, rather than before bedtime.
- NovoMix 30 FlexPen
- PenMix 30, PenMix 40, PenMix 50
- Humulin 30/70
- Mixtard 30
- Humalog Mix 25, Humalog Mix 50
Read more about insulin pens and needles and insulin syringes and needles.
Insulin dose and timing
Your doctor or nurse will work with you to find the best insulin to meet your needs. This can be made up of a rapid-acting insulin and an intermediate or long-acting insulin, or it can be insulin and tablets.
The timing of your insulin in relation to food and exercise is important. Your doctor or nurse will advise you when it's best to use your insulin. It's best to avoid hot showers or baths within 30 minutes of an insulin dose. Your doctor or nurse will advise what to do if you miss a dose of insulin.
Choosing an injection site
Insulin should be injected into the fatty tissue under your skin. Commonly used sites are the tummy area, thighs and buttocks – the tummy area is the preferred one. You need to move injection sites so that your skin does not become lumpy. Lumpy skin can affect how your body absorbs insulin. Also do not inject insulin on any scar tissue. Read more about insulin injection sites.
Drinking alcohol can affect blood glucose and the dose of insulin may need to be changed. Avoid or limit alcohol intake. Do not drink alcohol on an empty stomach. Eat before or while you are drinking alcohol. Read more about diabetes and alcohol.
If you are unwell and not eating
If you are unwell, such as throwing up (vomiting) or have runny poos (diarrhoea), and not eating as you usually do, your insulin dose may need to be changed. Contact your doctor or nurse for advice. Read more about diabetes sick day plan.
How to store insulin
It is very important that insulin is stored correctly. Incorrectly stored insulin can stop it from working properly.
- Unopened insulin can be stored in the fridge until it is used.
- Do not store insulin in the freezer.
- Once opened, insulin vials, cartridges or pre-filled pens can be kept at room temperature but must be discarded after 4 weeks .
- When keeping insulin in use at room temperature, ensure it is not exposed to sunlight.
Read more about storing and handling insulin.
Side effects when using insulin
- Lumpiness at the site of injection: You may notice fatty lumps on the surface of your skin at the injection site. Change the injection site and contact your doctor or nurse if you notice pain or redness.
- Low blood sugar: Sometimes insulin may lower your blood sugar too much – called hypoglycaemia. This may cause you to feel weak, faint, dizzy, drowsy or irritable. You may get a headache, tremor (shakes) or blurred vision. If this occurs, drink something sweet such as a small glass of sweetened soft drink or fruit juice, or lollies. Make sure your family and friends know what to do too. Tell your doctor or nurse if this happens a lot. Your dose of insulin may need to be changed.
New Zealand Formulary Patient Information:
Insulin pens – how to inject insulin
It is important to inject insulin correctly. Ask your diabetes nurse, pharmacist or doctor for advice. The following information is a guide.
Priming your insulin pen
Priming your insulin pen means removing any air from inside the insulin cartridge, to ensure you get an accurate dose. It also ensures your pen is working correctly. It is important to prime your insulin pen with at least 2 units of insulin before every injection.
- To prime your pen, use the dose selector knob to dial 2 units.
- Hold your pen with the needle pointing up, into the air.
- Tap the cartridge gently to collect air bubbles at the top.
- Push the dose selector knob until it stops and zero is seen in the dose window. Hold this for a few seconds.
- You will see drops of insulin at the tip of the needle.
- If you do not see insulin drops, then repeat the process, or change the needle and repeat the priming steps.
- Note: tiny air bubbles are normal and will not affect your dose.
If 2 units are used for priming each injection, this can add up to between 1–3 additional 3mL cartridges in 3 months. Tell your doctor to prescribe enough insulin to allow for priming with each injection.
Selecting your dose
- Wash your hands with soap and water before injecting.
- Use a new needle for every injection to minimise pain. Reusing needles can lead to bruising, bleeding and infection.
- Dial the number of units you are going to inject by turning the dose selector knob.
- Inject insulin into the fatty tissue just under your skin, in the abdomen or tummy area, about 5 cm away from your belly button. Read more about injection sites below.
- Hold the pen in your hand with your thumb or finger on the dose selector knob at the end of the pen.
- If you are using an 8 mm (or longer) needle, pinch up your skin on your stomach then slide the needle into the skin fold at a 90º angle. If your needle is less than 8 mm long, don't pinch up your skin.
- Push the dose selector to inject the dose, relatively slowly, as far as it will go. The dose window should read zero.
- Leave the needle in for 6 seconds.
- Continue to push in the dose selector knob while you remove the needle.
Storing your insulin pen
- Insulin pens that you are currently using are not kept in the fridge.
- Spare pens can be kept in the fridge but once they are in use, and have a needle attached, they should be kept out of the fridge.
- If they remain in the fridge, insulin can leak out. Also, pens that are frequently moved in and out of the fridge can accumulate air bubbles.
Tips to minimise pain when injecting insulin
Injecting insulin can cause discomfort, but it should not be painful. Here are a few tips to minimise pain when injecting:
- Make sure your stomach muscles are relaxed.
- Use insulin and a needle at room temperature.
- Push the needle in quickly and hold for about 10 seconds before removing the needle.
- Try not to wiggle the needle as you’re injecting or removing it.
- Always use a new needle for every injection.
- Move the site of injection – do not inject into the same site you last used. This will help avoid scarring and reduce pain.
The following links provide more information on injecting insulin. Be aware that websites from other countries may have information that differs from New Zealand recommendations.
How to inject insulin Diabetes.co.uk, UK
Injecting insulin for type 1 diabetes NPS MedicineWise, Australia)
- Insulin prescribing SafeRx Waitematā DHB, NZ, 2017
- Insulin injection know-how American Association of Diabetes Educators, US