There are four safe areas for insulin injections: the side of the thighs, the back of the upper arms, the abdomen (belly) and the upper outer buttocks. It is important to rotate insulin injection sites.
Select a safe part of the body to inject insulin
- On the thighs, use the top and outer areas only. Do not use the inner side or back of the thigh. Stay about three to four finger-widths away from the knee and groin.
- On the upper arms, use the fleshy area on the side and back of the arms. Avoid the muscle in the shoulder. Stay three to four finger-widths away from the elbow.
- On the abdomen, inject in the area right across the abdomen, from just below the ribcage to well below the belt line. Stay about two finger widths away from the belly button.
- Inject the outer top of the buttocks, where a pant belt would sit.
Insulin may be absorbed differently from one site to another. Also, insulin injected over an exercising muscle may be absorbed more quickly. For that reason, it is best to rotate and inject insulin into fatty areas in the parts of the body mentioned above. If there is no fat, then rotate injections amongst the other designated injection sites.
Injections are done in a pattern to avoid using exactly the same site over and over. Make sure that each injection is about an inch (2.5 cm) or two finger widths from the one done before. Try to work in straight, even rows about an inch apart. This way you are more likely to remember where the last injection was given.
Rotating insulin injection sites
Many people with diabetes, children especially, develop “favourite” injection sites where there seems to be less pain and injections seem easier. You should always rotate injection sites regardless of how you give the insulin: pen, syringe or insulin pump.
If you use the same small area many times, the fat tissue below the skin sometimes swells, a condition called lipohypertrophy. This creates large bumps that absorb insulin poorly.
Too many injections into the same site may cause hard scar tissue to form under the skin, which also affects the body’s ability to absorb insulin.
These bumps and scar tissue will disappear if the area is left alone for a while, usually two to three months.
To avoid these problems, alternate a few different sites for insulin injection. At each clinic visit, a member of the diabetes team will look at the injection areas to help you select a site and prevent lumps or bumps.
Tips for rotating insulin injection sites
In the beginning, try to use a different injection area each time so your child realizes the number of areas that can be used and does not become fearful of using any of the sites.
Once you have tried the arms, thighs, abdomen, and buttocks a few times, create a systematic approach to site rotation.
- Choose one general area and use all possible sites in that area before moving to the next.
- Make sure that each injection is about an inch (two finger-widths) from the last injection.
- Try to work in straight rows.