Registered Nurses' Association of Ontario

Nursing Best Practice Guidelines

General Guidelines for Mixing Insulin in a Syringe

To mix two kinds of insulin in the same syringe

  • Pull the plunger down until the tip of the plunger is at the line for the number of units you need and inject air equal to the amount of insulin you require into the cloudy vial. Pull the needle out without taking insulin out then inject air into the clear vial.
  • Turn the vial of clear insulin upside down. Slowly push plunger up and down and then pull plunger down until you have your correct dose of insulin. (N.B. If insulin is being withdrawn from a cartridge, air is not to be injected into the cartridge.)
  • Check that you have the correct amount of insulin and that there are no large air bubbles in the syringe. Remove the syringe.
  • Carefully insert needle into vial of cloudy insulin and turn the vial upside down.
  • Slowly pull the plunger down until you have the right total dose (the clear plus the cloudy). _____units + ______units = ____units
  • Remove syringe
  • Pinch skin up gently and push needle into the skin at a 90° angle. Push the plunger down to inject insulin