Why Should I Rotate Where I Inject Insulin?

Insulin Site Rotation Gives More Consistent Blood Sugar Control

Girl holding a syringe with insulin
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Question: Why Should I Rotate Where I Inject Insulin?

I have type 2 diabetes and I recently needed to start injecting insulin. I've been told that I shouldn't inject it in exactly the same spot each time. Why is this advice given? Is it because it will affect how the insulin gets absorbed? Or is it because the injections might cause skin problems? Does it matter whether I give all of the injections on my abdomen but in different sites, or should I be rotating injection sites to my thigh or buttocks as well?

Answer: Site Rotation is Recommended for Insulin Injections

Rotating insulin injection sites helps prevent damage to the skin and underlying tissue. Insulin can be irritating and cause hardening of the skin (lumps, bumps, and dimpling) and weakening of fatty tissue under the skin. Over time, the thickened skin may not have nerve endings anymore. Shots may become painless as a result. You may think a painless injection is a positive, but actually that's a sign that the skin is becoming more damaged and therefore it is not a good sign.

But the biggest danger of continuing to inject at the same area of your body is that damaged tissue doesn't absorb insulin as easily or at the correct rate. The more damaged the skin at the injection site is, the more difficulty controlling your blood glucose levels may be.

Give Mealtime Insulin Injections in the Same General Area But Rotate Sites

You have probably been told to give your mealtime injections in your abdomen, as they work fastest when you inject them at that site.

The insulin enters your blood more slowly if it is injected in the upper arm, thigh, or buttock rather than the abdomen.

But you could choose to always do your pre-breakfast injection on your upper arm and your pre-dinner injection on your abdomen. You will have the most consistent blood sugar results from insulin if you inject it in the same general area at the same time of day, but change the exact site each time.

What If I Have Skin Lumps from Insulin Injections?

If you develop lumps and bumps at injection sites, avoid the area of the bump for several months. It can take awhile for it to go away. That area will absorb insulin differently and this can affect your blood sugar levels.

If you have a lump under the skin immediately after an injection, it could be that you didn't get the needle all the way into your fat tissue and the insulin was injected just under the skin. You may need to practice your injection technique or use a longer needle or an insulin pen that has a longer needle.

If you have any red, irritated lumps or a rash at the injection site, you should be concerned about possible skin infection. Discuss this with your doctor to keep from having an infection spread. You may have to change sites while the infection is being treated and cleared up.


"Insulin Injection Sites." Health Information. 04 APR 2004. University of Wisconsin Hospitals and Clinics Authority. 27 Sep 2007.

Insulin Routines, American Diabetes Association, July 29, 2015.

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