If you have diabetes, your doctor may prescribe insulin to help regulate your blood sugar. Insulin is a hormone normally produced in the pancreas, but in some types of diabetes, your pancreas doesn't produce it in sufficient quantities. This means that after a meal, your blood sugar levels can rise drastically, which is unhealthy. While many diabetics -- even children -- can eventually learn to administer their own insulin, it's possible to give an insulin injection to another person.
Identify a location for the injection. There are many possible sites, including the upper, outer arms, upper thighs, belly, buttocks and hips. Drugs.com explains that a diabetic absorbs insulin fastest when it's injected under the skin of the belly, but it's important to rotate the injection site to prevent injury to the skin. Ask the person you're helping for suggestions on a site that he hasn't used recently.
Wash your hands. Because you'll be administering an injection, you'll want to ensure that your hands are as clean as possible so as to minimize the risk of introducing infection. You don't need to use fancy antibacterial preparations; washing with soap and water is sufficient. Wipe the membrane on top of the insulin bottle with an alcohol swab to remove any contamination.
Take the cap of the syringe and pull the plunger back to fill the syringe with air up to the line on the syringe that corresponds with the amount of insulin the diabetic person needs. Stick the needle into the bottle of insulin and depress the syringe plunger to add all the air in the syringe to the bottle. This helps prevent formation of a vacuum in the insulin bottle as you extract the medication. Turn the bottle upside down with the syringe still in place and draw back the plunger to fill the syringe with insulin to the line on the syringe that corresponds with the correct dose.
Wipe a small area of skin where you'll be giving the injection with a clean alcohol swab. Pinch a small amount of skin between your thumb and pointer finger and insert the needle all the way at a 90 degree angle to the skin. Release the pinch, then inject the insulin. Be sure you're injecting the insulin subcutaneously -- below the skin -- rather than into the muscle. If you're injecting a child or very slender individual without much body fat, you may need to insert the needle into the pinch of skin at a 45 degree angle, explains the American Diabetes Association in an article titled "Insulin Administration."
Wait for 5 seconds before removing the needle; this will help prevent insulin from seeping out through the injection site which could reduce the effectiveness of the dose. If you see blood or clear fluid after you remove the needle from the diabetic's skin, put pressure on the injection site -- or have the diabetic put pressure on the site -- for several seconds, suggests the American Diabetes Association.
Dispose of the insulin syringe appropriately, by placing it into a puncture-resistant container. Do not try to recap the syringe, as this increases the risk you'll accidentally puncture yourself. Similarly, you should not try to bend or break the needle on the syringe before placing it in the disposal container. You should not throw an insulin syringe in the trash; if you're in public, there are insulin disposal containers in many restrooms.