Insulin is a hormone that helps cells use glucose (sugar) for energy. It also helps balance out blood sugar levels by preventing them from getting too high or too low. In type 1 diabetes, the body does not make insulin.
Diabetes is normally managed with a mix of insulin injections, other medications, diet, and exercise. For people with insulin-dependent diabetes, this may seem difficult at first. However, you can successfully manage diabetes with the support of your healthcare team, determination, and a little practice on your part.
There are different ways to take insulin, including syringes, insulin pens, insulin pumps, and jet injectors. Your doctor will help you decide which is best for you. Syringes remain a common method of insulin delivery. They’re the least expensive option and most insurance companies cover them.
Syringes vary by the amount of insulin they hold and the size of the needle. They’re made of plastic and should be discarded after one use.
Traditionally, needles used in insulin therapy were 12.7 millimeters (mm) in length. As reported in Diabetes Technology & Management, recent research shows that smaller 8 millimeter (mm), 6 mm, and 4 mm needles are as effective, regardless of body mass. This makes insulin injection less painful than it was in the past.
Insulin is injected subcutaneously, which means under the skin. In this type of injection, a short needle is used to inject a drug into the tissue layer between the skin and the muscle. Medication given this way is usually absorbed more slowly than if injected into a vein, sometimes over a period of 24 hours.
Insulin should be injected into the fatty tissue just below your skin. If you inject the insulin deeper into muscle, your body will use it too quickly. This can lead to dangerously low blood glucose levels.
People who take insulin daily should rotate their injection sites. This is important because using the same spot over time can cause lipodystrophy. In this condition, fat either breaks down or builds up under the skin, causing lumps or indentations that interfere with insulin absorption.
You can rotate to different areas of your abdomen, keeping injection sites about an inch apart. Or you can inject insulin into other parts of your body, including your thigh, arm, and buttocks.
The preferred site to inject insulin is the abdomen. Insulin is absorbed more quickly and predictably there, and this part of your body is also easy to reach. Select a site between the bottom of your ribs and your pubic area, steering clear of the area surrounding your navel.
You’ll also want to avoid areas around scars, moles, or skin blemishes. They can interfere with the way your body absorbs insulin. Stay clear of broken blood vessels and varicose veins as well.
Inject into the top and outer areas of your thigh, about 4 inches down from the top of your leg and 4 inches up from your knee.
Use the fatty area on the back of your arm, between your shoulder and elbow.
Before injecting insulin, it’s vital to check its quality. If it was refrigerated, allow your insulin to come to room temperature. If the insulin is cloudy, mix the contents by rolling the vial between your hands for a few seconds. Make sure not to shake the vial, and don’t use insulin that is grainy, thickened, or discolored.
Follow these steps for safe and proper injection:
Gather the supplies:
- Medication vial
- Needles and syringes
- Alcohol pads
- Puncture-resistant “sharps” container for proper needle and syringe disposal
Wash your hands thoroughly with soap and warm water. Be sure to scrub between fingers, the backs of your hands, and under fingernails. The Centers for Disease Control and Prevention (CDC) recommends lathering for 20 seconds – the time it takes to sing the “Happy Birthday” song twice.
Hold the syringe upright (needle on top) and pull the plunger down until the tip of the plunger reaches the measurement equal to the dose you will inject.
Remove the caps from the insulin vial and needle. If you've used this vial before, wipe the stopper on top with an alcohol swab.
Push the needle into the stopper and push the plunger down. The air replaces the amount of insulin you will withdraw.
Keeping the needle in the vial, turn them upside down. Pull the plunger down until the top of the black plunger reaches the correct dosage on the syringe.
If there are bubbles in the syringe, tap it gently and the bubbles will rise to the top. Push the syringe to release the bubbles back into the vial. Pull the plunger down again until you reach the correct dose.
Set the insulin vial down and hold the syringe as you would a dart, with your finger off of the plunger.
Swab the injection site with alcohol pad. Allow it to air dry for a few minutes before inserting the needle.
To avoid injecting into muscle, gently pinch a 1- to 2-inch portion of skin. Insert the needle at a 90-degree angle. Push the plunger all the way down and wait for 10 seconds. With smaller needles, this pinching process may not be needed.
Release the pinched skin immediately after you’ve pushed the plunger down and remove the needle. Don’t rub the injection site. You may notice minor bleeding after injection. If so, apply light pressure to the area with gauze and cover with a bandage if necessary.
Place the used needle and syringe in the puncture-resistant sharp’s container.
Use these tips for more comfortable and effective injections:
- When using an alcohol swab, it may sting less if you wait for the alcohol to dry before injecting yourself.
- You can numb your skin with an ice cube for a couple of minutes before swabbing it with alcohol.
- Avoid injecting in the roots of body hair.
- Ask your doctor for a chart to keep track of your injection sites.
In the United States, people use more than 3 billion needles and syringes each year, according to the Environmental Protection Agency. These products are a risk to other people and should be disposed of properly. Regulations vary by location. Find out what your state requires by calling the Coalition for Safe Community Needle Disposal at 1-800-643-1643 or checking their site at http://www.safeneedledisposal.org.
You aren’t alone in treating your diabetes. Before beginning insulin therapy, your doctor or health educator will show you the ropes. Remember, whether you’re injecting insulin for the first time, running into problems, or just have questions, turn to your healthcare team for advice and instruction.