How to Inject Insulin

Injecting at the proper depth is an important part of good injection technique. Most healthcare professionals recommend that insulin be injected in the subcutaneous fat, which is the layer of fat just below the skin. If you inject too deep, the insulin could go into muscle, where it's absorbed faster but might not last so long (and, it hurts more when you inject into muscle). If the injection isn't deep enough, the insulin goes into the skin, which affects the insulin's onset and duration of action.  See which insulin injection sites are best.


Most people pinch up a fold of skin and insert the needle at a 90° angle to the skin fold. To pinch your skin properly, follow these steps:

• Squeeze a couple of inches of skin between your thumb and two fingers, pulling the skin and fat away from the underlying muscle. (If you use a 5 millimeter mini-pen needle to inject, you don't have to pinch up the skin when injecting at a 90° angle; with this shorter needle, you don't have to worry about injecting into muscle.)
  
  
• Insert the needle.
  
  
• Hold the pinch so the needle doesn't go into the muscle.
  
  
• Push the plunger (or button if you're using a pen) to inject the insulin.
  
  
• Release the grip on the skin fold.
  
  
• Remove the needle from the skin.

Note that not everyone injects at a 90° angle. If you inject into an area of the body that has less fat, you may need to inject at less than a 45° angle, to avoid injecting into a muscle. The angle you should use to insert the syringe or pen needle into your body depends on your body type, the injection site, and the length of the needle that you use. Your healthcare professional can help you determine the right angle of injection for you.