Insulin overview

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 the 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.

Injection sites

Insulin should be injected into the fatty tissue under the skin. The abdomen or tummy area, about 5 cm away from your belly button, is usually a good place. It is easy to reach and insulin absorbs well from this site.

• Other areas such as the buttocks, thigh or outer arm are usually not preferred because they are harder to reach, insulin absorbs slower and absorption may be affected by exercise. 
• Do not inject your dose into the muscle, this can be painful and affects the absorption of insulin in the body.
  
  • If you think you are injecting into the muscle, talk to your diabetes nurse, pharmacist or doctor.
• Move injection sites so that the skin at the site of injection does not become lumpy. Lumpy skin can affect how your body absorbs insulin.  You can move from one side of your abdomen to the other side each time.
• Do not inject insulin into any scar tissue.
  
  

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. 

Learn more

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) 

References

1. Insulin prescribing SafeRx Waitemata DHB, 2017
2. Injection technique in insulin therapy Nursing Times, 2012
3. Insulin Injection Know-How American Association of Diabetes Educators

In New Zealand insulin is available as 10 mL vials and 3 mL cartridges.

• Insulin from the 10 mL vial is injected using a syringe with a needle.
• Insulin from the 3mL cartridgeare given using an insulin pen. There are 2 types of insulin pens:
  • Reusable pen which allows you to replace the insulin cartridge when it's empty or expired – The cartridge can be removed from the pen, thrown away and a new cartridge is fitted into the same pen.
  • Disposable pen in which a cartridge is pre-fitted into the pen and cannot be removed. When the insulin runs out, the entire pen is thrown away and a new pen is required.  

Syringes & needles

• There are 3 different sized syringes available in New Zealand: 0.3mL, 0.5 mL and 1 mL.
• The strength of all insulins in New Zealand is 100 units/mL, so a 0.3 mL syringe has doses of up to 30 units. A bigger syringe is used for larger doses. 
• People who mix insulins in the syringe may prefer a larger syringe (0.5 mL or 1 mL) to allow for ease of mixing.
• Syringes have attached to them a variety of different sized needles. Needle sizes are measured by their thinness (gauge) and their length (in mm); for example 31 gauge x 8 mm.
• The higher the gauge, the thinner the needle; for example, a 31 gauge needle is thinner than a 28 gauge needle. 
• People who use syringes more than once may prefer a stronger (lower gauge number) needle. If the syringe is being used for a young child the finer, shorter (31 gauge, 8 mm) needle may be preferred. 

Syringe sizes available in New Zealand¹

• 0.3 mL with 29 gauge x 12.7 mm needle
• 0.3 mL with 30 gauge x 8 mm needle
• 0.3 mL with 31 gauge x 8 mm needle
• 0.5 mL with 29 gauge x 12.7 mm needle
• 0.5 mL with 31 gauge x 8 mm needle
• 1 mL with 27 gauge x 12.7 mm needle
• 1 mL with 29 gauge x 12.7 mm needle
• 1 mL with 31 gauge x 8 mm needle.

If you are unsure of which syringe and needle size is best for you, talk to your diabetes nurse, pharmacist or doctor.

Funding

In New Zealand, you can have 100 subsidised syringes on a prescription if insulin is also on the prescription or the prescription is endorsed as being for a patient using insulin. Your doctor can write more than one prescription. Read more about syringes from Diabetes NZ.

Insulin pens

Insulin pens are similar in size and shape to a writing pen. Pens make measuring and injecting your insulin easier and are easy to carry around. Insulin pens are not pre-fitted with needles. A suitably sized needle has to be attached to the pen. There are 2 types of pen devices available in New Zealand: reusable and disposable.

Reusable pens

Reusable pens allow you to replace the insulin cartridge. When the cartridge runs out or expires, it is removed from the pen, thrown away and a new cartridge is fitted into the same pen. 

In New Zealand, insulin is supplied by Novo Nordisk, Eli Lilly and Sanofi-Aventis. It is important to use the correct insulin brand in the correct pen. For example, Lilly pen will use Lilly insulin cartridges, a Novo-Nordisk pen will use Novo-Nordisk insulin cartridges, etc.

Reusable pens are available at no cost from Diabetes Clinics and pharmacies.

Disposable pens

These pens have an insulin cartridge pre-fitted into the pen that cannot be removed. When the insulin runs out, the pen is thrown away and a new pen is required.

Needles

Insulin pens are not pre-fitted with needles. A suitably sized needle has to be attached to the pen. Needle sizes are measured by their thinness (gauge) and their length (in mm); for example 31 gauge x 8 mm. The higher the gauge, the thinner the needle; for example, a 31 gauge needle is thinner than a 28 gauge needle. 

Needle sizes available in New Zealand²

• 29 gauge x 12.7 mm
• 31 gauge x 5 mm 
• 31 gauge x 6 mm 
• 31 gauge x 8 mm 
• 32 gauge x 4 mm 
• 28 gauge x 12 mm 
• 30 gauge x 8 mm.

Which device: syringe or pen?

The decision to use syringes or pens is a personal one. Here are some points to think about:

• Insulin pens are easy to carry around, and make measuring and injecting your insulin easier. Injections can be administered discretely. Most pens hold 300 units of insulin and allow delivery of up to 60 to 80 units at a time. Most insulins are available as pens.
• Syringes hold up to 100 units. They may be best if you use mixed insulins or if you're giving insulin to a child.

Talk to your diabetes nurse, pharmacist or doctor for more advice. Read more about insulin injection technique.

Insulin pumps

Short and rapid acting insulins can also be given by a portable insulin pump. This delivers continuous insulin and can be activated to give extra insulin at meal times. These pumps can be useful for people who have hypoglycaemia often, or if their levels are difficult to control. There are certain criteria for funding, and many options available. For more information, see sub-cutaneous insulin infusions (insulin pumps), Ministry of Health, NZ.

Learn more

Pens, needles and syringes Diabetes New Zealand

References

1. Syringes New Zealand Formulary
2. Needles New Zealand Formulary

Information for clinicians

Alerts

• Reducing harm from high-risk medicines - insulin (HQSC)

Medsafe NZ Data Sheets

• insulin

Drug Formulary NZ

• insulin

 

Medsafe Prescriber Updates

• Lantus (insulin glargine) and cancer - no conclusive evidence of higher risk (November 2009)

Best Practice Update (BPAC)  

• Initiating insulin for people with type 2 diabetes (February 2012)