Administrating Insulin and Insulin Analogues

How to Inject Insulin

Size matters: a photo comparing a syringe used 15 years ago with one of today's devicesSize matters!  A comparison of a needle and insulin syringe used 15 years ago with a more modern needle of today's pen devices.


How is insulin injected?

Cross-section showing the surface of the skinInsulin is injected in to the layer of fat just beneath the skin using a needle and syringe or using a pen delivery device.

Does it hurt?

Injecting insulin using modern day needles is relatively painless. Pricking your finger using a lancet for blood glucose estimation is far more painful.

What are the suitable sites?

  • Front or outer aspect of both thighs
  • Upper outer area of buttocks
  • Skin over the tummy below the umbilicus
  • Outer and rear surfaces of upper arms

Care of injection sites

Rotate sites every day. If you use the same area, aim to move the site of injection and inch or more

Is there a difference in absorption between different sites?

Yes. Insulin tends to be absorbed more quickly from the abdomen (‘tummy’) and upper arms and more slowly from thighs and buttocks. You can use this to your advantage such as by giving your morning injection into your abdomen and the evening dose in your thigh.

Do I need to disinfect the skin?

It is unnecessary to use alcohol to cleanse the skin – it stings and inflicts needless pain.  Ensure your hands have been washed with soap and water and that the area of injection is similarly clean.

Delivery of injections

If you are using a mixture - mix the insulin well!

Mix the insulin well Position the syringe and make the injection

  • Thin built people with little fat should lift up a fold of skin and inject the insulin into it.
  • If you have a plentiful layer of fat, stretch the skin slightly before injecting.
  • Place the needle against a bit of skin that is a decent distance from the last injection. Avoid superficial veins that you can see – don’t worry about the ones that you can’t !
  • Position the pen or syringe at right angles to the skin and insert the needle up to its full depth before injecting. Don't inject too quickly or press too hard on the plunger.
  • Press down on the plunger and allow time (a few seconds) for the dose to be delivered before withdrawing the needle. This reduces the chance of insulin leaking out. Massage the area gently. Don't be surprised if a droplet of blood or insulin comes out with the needle. This is quite normal.
  • Place the used needle in your sharps container.

How to inject using a syringe

Please refer to the separate page on this subject.

How to reduce pain

  • enter the skin quickly
  • do not manipulate the needle around or change direction once inserted
  • avoid re-using disposable needles
  • ensure insulin is at room temperature
  • use a shorter needle and pich up a skin fold if the above measures do not work

Injection site problems

  • You may notice bruising around the injection. This is due to piercing of tiny blood vessels.
  • ‘Lipohypertrophy’ – sometimes you may find you have developed ‘lumpy’ areas at injection sites. This is due to an increase in fatty tissue at the site of injection. This is due to insulin. It is harmless though sometimes unsightly. Absorption of insulin can be variable from these lumpy areas and you should avoid injecting into such fatty lumps.
  • ‘Lipoatrophy’ – this refers to loss of fat at the injection site which may result in visible depressions of the skin
  • Insulin leaks out of the injection site – if this happens try using a longer needle. Also try to leave the needle in for longer - approx 10 secs before withdrawal.


Dr Nishan Wijenaike MD, FRCP
Consultant Diabetologist
West Suffolk Hospitals Diabetes Service
October 2002
Update: November 2007