Choosing Insulin-Injection Sites

Choosing a good site for your insulin shot means more than choosing a spot that’s not bony or unreachable. It also means knowing how insulin absorbs from different areas and choosing a spot with the speed you need.

Why changing site is a good idea

Changing shot locations is called "site rotation". There are two reasons to rotate:


Using the same site over and over can damage the tissue under the skin. (human insulins are less likely to cause such damage)

Different body regions differ in how they absorb insulin. So changing sites lets you fine-tune your insulin absorption to your life.

The four body regions

For most people, four body areas have enough fat to inject into: the abdomen, buttocks, thighs, and upper arms.

The abdomen absorbs insulin the fastest. The arms are pretty fast, too. In contrast, the buttocks are slower, and thighs are the slowest. The abdomen has the most predictable absorption. Absorption in arms, buttocks, and thighs varies more.

To take advantage of these differences, try:


Taking breakfast and lunch shots in the arms or abdomen so that the insulin is ready for use quickly.

Taking dinner and bedtime shots in the thighs and buttocks so that the insulin covers the night better.

Each person is unique. You may respond differently than the average person to injections in the different sites. So it’s worthwhile to track your glucose levels with care when you first start site rotation. Work with your doctor or diabetes educator to find out which regions give you the best control at different times of the day.

Injection pointers


Use the outside part of your arms.

Use the tops and outside part of your thighs.

Within each body region, rotate sites. For example, start each Monday on the right side of your abdomen and work your way to the left side by Sunday.

Each shot should be at least a finger’s width distant from the previous shot in that region.

Whatever plan you choose, be consistent. You can then predict when your insulin will peak and plan your food and exercise schedule to match. Randomly choosing sites will cause ups and downs in your glucose.

Don’t inject into a region that has been exercised recently or will be soon. Exercising increases blood flow and makes long-acting insulin get absorbed faster than usual.

Never inject into muscle.

Don’t inject near a mole or scar.

If you get a lumpy fat deposit where you inject, avoid that lump in the future. Insulin does not absorb as well from these lumps.
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