Stay at least two inches away from the belly button, or any scars or moles.
Inject at least 4 inches (or approximately one hand-width) above the knee and at least 4 inches down from the top of the leg. The best area on the leg is the top and outer area of the thigh.
Inject into the fatty tissue in the back (not the side) of the arm between the shoulder and the elbow.
Inject into the hip or “wallet area” and not into the lower buttock area.
A few additional points
To make sure that your insulin is absorbed consistently, it may be best to give all injections in one or two areas of the body and rotate where you inject the insulin within that site for a period of time.
Use a different site for each time of day. For example, inject your morning insulin in your stomach and your evening insulin in your thigh. Be sure to rotate within the site.
Physical activity may increase insulin absorption. It’s best not to inject in your arm or thigh if you have just exercised or plan to exercise (your arms would absorb insulin quickly if you were doing a set of bicep curls, for instance). So your stomach may be the best site choice if you will be physically active.
Hot temperatures tend to increase insulin absorption, while cold temperatures can decrease absorption. Be careful about injecting insulin after taking a hot shower, a bath or being out in the cold.
Smoking may decrease insulin absorption, which is another good reason to quit!