Insulin Injection Sites: Where and How to Inject Insulin?

Last updated on March 15th, 2023

Individuals with type 2 diabetes cannot use insulin properly. Either the pancreas stopped producing enough insulin or cells cannot use the produced insulin.

In such cases, they are advised to go on insulin therapy or insulin injections.

Importance of Insulin 

Human insulin or insulin injection in the form of solution or suspension replaces the normal insulin produced by the body. It helps to regulate blood glucose levels. 

Human insulins are generally injected subcutaneously at various parts of the body. These insulin are injected in different quantities or dosages as per each individual’s need.

Also, there is more than one insulin used to keep sugar levels in check. Your doctor suggests dosage, frequency, and brand of human insulin based on your physiological requirements. 

Diabetes is a metabolic disorder in which cells do not use insulin properly and become insulin resistant. It increases sugar levels in the body. These sugar levels cause various health conditions if they remain untreated or unattended.

Diabetes is an irreversible condition but sugar levels are not. One can manage these spiking sugar levels through a modified lifestyle that includes diet, exercise, and medications.

In some cases, when these factors do not help, the doctor suggests starting insulin therapy or insulin injection. 

The complications that a diabetic patient can face are cardiovascular diseases, kidney diseases, nerve damage, eye and vision diseases, stroke, and other life-threatening diseases.

Treating these high sugar levels will help to reduce the risk of these chronic health complications. 

Diabetes Complication that can be prevented by using insulin injections: 

A controlled sugar level increases the quality of life and span of life to multiple folds. Insulin therapy can be a light to those diabetic patients who are struggling to manage their high glucose levels every day. 

Also Read: Insulin Resistance Diet for Diabetes

What is Insulin Injection?

Human insulin is available in two forms: solution (liquid) and suspension (liquid with particles that will settle on standing). They are used under the skin or subcutaneously. One can use these injections more than once daily prescribed by the doctor.

Insulin injections are available in vials, disposable dosing devices, and cartridges. The usage of these is different from each other. Vials are used with injections or syringes, and disposable dosing devices (insulin pumps) come with a device that is used as per instructions. To use cartridges, an insulin pen is used directed by your doctor. 

In some cases, this insulin is used as IV (Intravenous). This is administered by a healthcare provider only. It requires some observation to monitor side effects as well. 

As mentioned above, insulin comes in different forms. The traditional way is vials or syringes. Other than this cartridges or insulin pens and disposable dosing devices or insulin pumps are two major methods used to inject insulin into the body. Which one is to be used is decided by your doctor as the best option for you.

Also Read: Health Benefits of Lemon

Insulin Injection Methods

A diabetic person needs to take insulin injections to control their high sugar levels. These insulins are injected from outside in a form of a liquid or suspension.

These injections are administered through various insulin injection methods. These are as follows:

Syringes or Vials

This is one of the most used methods. It is also a pocket-friendly method. This insulin injection is used subcutaneously or under the skin. This is used between the fatty layer of skin and muscles. Be careful while injecting it as injecting is deep may be painful and can cause hypoglycemia.

The reason is when you inject it deep into the muscles, it is absorbed more quickly into the blood and reduces sugar levels quickly. Thus its effect won’t stay long. These syringes come in different sizes and their needle sharpness differs from one another.

It is advised to use these syringes on different areas of the skin as using them in one place can create complications. Pricking on one area can cause fat breakage or accumulation at one spot and reduces the absorption of insulin effectively. This condition is called lipodystrophy.

These syringes are used on various sites of the body like abdomen, thighs, and arms to prevent lipodystrophy and are less painful. 

Also Read: ICMR Guidelines for Type 1 Diabetes Management

Cartridges or Insulin Pen

The second method, diabetic patients use to administer insulin injection is the Insulin pen. Insulin pens are more popular among diabetic patients because of the accuracy of the dosages and their easy usability.

These pumps are easy to use than syringes or vials. The major reasons for the popularity of these pens or cartridges are:

  • Very convenient to use 
  • Accuracy of described dosage
  • Less painful than syringes
  • Portable
  • Pre-set insulin levels 
  • Time-saving
  • Easy to use and store both

These pens come with a pre-set dosage that helps people to take the right amount of dosage. In syringes, less than 20% of people feel the accuracy of the designated dose. There are two types of insulin pens:

Disposable Insulin Pen:

These pens come with an insulin-filled cartridge and can be disposed of after use.

Reusable Insulin Pen:

One can reinstall the new cartridge in a reusable insulin pen.  

Important Tips before buying an Insulin Pen:

  • Brand of insulin suggested by the doctor In the case of the reusable pen, keep durability and quality in mind
  • Size of the pen for insulin dosage
  • Buy an insulin pen you can use if your dosage increases 
  • Size correction enablement if doses are not administered correctly
  • More dose dial numbers 

Disposable Dosing Device or Insulin Pump

These are small computerized devices and have pre-schedule insulin dosages. You can attach it under your clothes or belts or pocket. It comes with an adhesive patch that can be attached to your stomach or arm.

People who face slow food absorption, planning a pregnancy, stopping insulin insertion during exercise, children, and people who cannot keep a log of their insulin injections are the major users of these pumps.

This is a painless method and works independently with little or no supervision. Some people find it easier as the body keeps on absorbing insulin as per its preset dosage. The “dawn phenomenon,” also known as early-morning high blood sugar, is managed with its aid.

Also read: Is Cauliflower Good for Diabetes Patients?

Where to inject insulin?

  • Abdomen
  • Thighs
  • Arm

These places have more fat and muscle and are considered the best areas to use insulin injections. 

  • In the case of the abdomen, the injected area covers the area from below the ribs to the above pubic region. One can use insulin injection anywhere from this designated place. This is considered the most effective area that absorbs insulin well and works to manage sugar levels. 
  • In thighs, it is used at the outer thigh between your knee and the top of the leg. 
  • One can also inject insulin into your arms below the shoulder and above the elbow. Make sure to use it on the lateral side of the arm where fat is more. 

These are considered safe and effective regions for insulin injections. Out of them, the abdomen is the fastest to show results followed by the thigh and arms. The lower back is also one of the preferred sites for insulin injections. 

Where not to inject insulin?

Absorption of insulin varies from one site to another so it’s important to pick the best absorption place for you. The abdomen is considered one of the best sites for better absorption.

Do not try to change the injection site more often but keep changing the exact place and move the site at the gap of one finger’s width. 

Rotate the injecting sites in the clockwise direction around the belly button. Keep at least 2 inches of gap between two adjacent sites.

Choosing one injection site can cause lipohypertrophy or accumulation of fatty lumps under the skin. Injecting in these regions will either prevent or cause irregular insulin absorption. This causes slow absorption of insulin which does not help to manage sugar levels properly.  

Although one can use insulin injection on the abdomen, arm, and thigh but do not inject insulin if these areas have:

  • Moles
  • Stretch marks 
  • Scars
  • Varicose veins
  • Blemishes
  • Near Joints
  • Do not use it on the inner thighs or near joints to avoid nerves and blood vessels.
  • Also, do not inject insulin into muscles as it is best absorbed via the fatty layer of the skin. Although it won’t be harmful if insulin is injected into the muscle, it will be absorbed more quickly. It can cause a sudden drop in sugar levels.  

Using insulin injections in above mentioned sites won’t be helpful and effective for blood glucose control. So choose wisely and consult your doctor to determine the best place for you for controlled sugar levels and healthy life.

How to Inject Insulin?

There are different methods based on the device one is using

How to use Insulin Syringes?

  1. Use a new syringe
  2. Pull its plunger down and fill it with the suggested dose of insulin
  3. If a bubble comes, push the syringe
  4. Now clean the area with an alcohol pad
  5. Now pinch the skin area and prick the needle
  6. Hold the syringe at 90 degrees and push the plunger
  7. Now pull out the needle
  8. Do not rub at the skin 
  9. Dispose of the needle in the puncture-resistant sharp container

How to use Insulin Pen?

  1. While using a new pen, take it out from the refrigerator 30 minutes before
  2. Now rub the insulin pen between your palms until it looks clear 
  3. Open the pen cap and clean it with an alcohol pad
  4. Attach new needle
  5. Set the dosage or quantity of insulin 
  6. Press injecting button and keep it there for 5-10 seconds
  7. Now pull out the needle
  8. Don’t rub the skin
  9. Dispose of the needle properly
  10. Put the cap on the insulin pen to reuse.

How to use Insulin Pump?

  1. Attach it to your body using an infusion set 
  2. Insert a needle or small tapered cannula under the skin of the belly, thigh, or hips. 
  3. It comes with an adhesive patch to use
  4. Pre-programmed the dosage for a few days  
  5. It infuses small amounts of insulin into the body as per requirement.
  6. You need to learn to use this device from a healthcare expert before being used to it.

Also Read: Is Cucumber Good for Diabetes?

What are the Side effects of Insulin Injection?

Although doctors advise you on insulin based on your sugar levels and health condition, some of them can show side effects of the dosage. These normal side effects can be:

  • Itching, swelling, and redness at the area of injection
  • Skin conditions like fat breakdown and excess fat build-up.
  • Digestive issues 
  • Overweight 

Other than these conditions, some alarming conditions require immediate doctor consultations. These are:

  • Dizziness
  • Palpitations
  • Breathing problem 
  • Excess sweating
  • Itching all over the body 
  • Rashes on the body 
  • Muscle cramps 
  • Weakness 
  • Swelling 
  • Sudden weight gain 

In such conditions, ask your doctor for medical help.

How to dispose of needles, syringes, and lancets?

It is important to dispose of all the needles, syringes, and lancets after using them. Leaving them unattended can be hazardous for others.

To dispose of them, first of all, after using any needles or other sharps, put them all in a sharps disposal container right away. Keep these containers away from the reach of kids and pets. When the container is filled almost 75% then dispose of these syringes in different ways as per your area guidelines.

A few ways to dispose of them are some designated or supervised sites like hospitals, pharmacies, medical waste areas, etc. One can also get rid of these syringes in hazardous waste collection trash boxes in your locality.

To manage this waste, if there is a special waste management facility available in your area where medical trash can be disposed of, then use that service.

Ask your pharmacist about the available medicine take-back program in your area. 

Also Read: Postural Hypotension Causes, Symptoms, Diagnosis and Treatment

Dietary tips for those who take insulin

Insulin units are based on your daily blood sugar levels and the type of food you eat. Your dietitian or doctor plans your diet to maintain your sugar levels with certain amounts of insulin units so do not make big changes in your diet.

Also, maintain your physical activity and exercise to keep your sugar levels under control. Do not skip your meals and add extra carbohydrates and sugar to your diet. It helps your insulin to work efficiently. 

Things to follow for those who take insulin

  • Always wear a diabetes identification bracelet in case of an emergency to recognize your health condition by others.
  • Keep your prescriptions with you about your medication and insulin.
  • Also, keep a note of your daily dietary supplements, vitamins, or minerals you are taking.
  • Go for a regular check-up for your HbA1C and blood glucose levels. 

Some Other Helpful Tips

  • If you have a drug or insulin allergy, let your doctor and pharmacist know right away.
  • How frequently should you check your blood sugar? Consult with your doctor
  • Ask your doctor if you need to check your blood sugar before operating machinery or driving if you have hypoglycemia, as it may affect your ability to do so.
  • Inform the surgeon or dentist that you are using human insulin if you are having surgery, including dental surgery.
  • Inform your doctor if you are expecting, intend to become pregnant, or are nursing a baby. Call your doctor if you become pregnant while taking human insulin.
  • Blood sugar levels may drop as a result of alcohol. Inquire with your doctor about whether drinking alcohol is safe while taking human insulin.

Also Read: Cushing Syndrome and Diabetes


Diabetes is an ongoing battle and the only way to win against it is to keep your sugar levels in check. Some diabetic patients can manage it through lifestyle modifications and medications but in some cases, Insulin injection is the only way.

These insulin injections are effective to control high glucose levels. Doctors suggest insulin dosage, frequency, and brand of injection for each individual so it varies from person to person.

Remember to follow all the directions given by a doctor or a healthcare professional. With some care and discipline, one can easily live a healthy life even after using insulin injections.

Also Read: Dyslipidemia: Types, Causes, Symptoms, and Treatment


Can I reuse my syringe?

It is best not to reuse the syringe after one use. Used syringes can carry some infections with them so it’s better to use a new one. In the case of insulin pens, one can reuse them up to 5 times with proper hygiene. 

How can I decrease pain when I inject insulin?

Follow a thorough method to minimize the pain. Always use a new needle, maintain hygiene, keep your syringe or needle at room temperature, inject at the best site, remove bubbles from the injection and use alcohol or spirit to clean the injection site. To lessen the pain, numb your skin with ice before injecting. Also, let the spirit or alcohol dry before using the injection.

What happens if you don’t rotate injection sites?

Using insulin injection in one place repeatedly causes lipohypertrophy. It is a condition where a lump of fatty tissue is formed beneath the skin. It resists insulin absorption so it is advisable to change insulin injection sites regularly. 

Can you inject insulin above the belly button?

Yes, the abdomen is the most suggested injecting site for insulin as it absorbs the insulin quickly. So you can inject insulin above the belly button. Do not use injection on the naval and just below the navel because of the fascia tissue that is unable to absorb insulin. 

Where on the thigh should you inject insulin?

Use insulin injection at the outer side of the thigh below the leg joint and above the knee. Do not use it on the inner thighs or near joints to avoid nerves and blood vessels.

Should you pinch the skin when using an insulin pen?

Insulin is injected into the fatty layer of the skin to get absorbed so make sure you are injecting your fatty layer and not your muscles. Before injecting insulin use this popular term “pinch an inch”. Pinch an inch of skin and then inject an insulin pen at a 90-degree angle in one go. It is more important if you are skinny or a child.

Where is injected insulin absorbed the fastest?

Insulin is the fastest absorbed by the abdomen so it is advised to have them on the abdomen for better results. But since one needs to change the injected site, insulin is also administered at the arms, thighs, and buttocks.

How Do You Know How Much Insulin to Use?

Insulin is administered before your meal which includes carbohydrates. The amount of insulin is determined by your sugar levels before meals and how many carbohydrates you are about to consume. In the case of basal insulin (usually around 120 glucose level), you are advised to take the preset amount of insulin suggested by the doctor and it could be 1 unit. In the case of bolus insulin (when you eat carbohydrates), you generally take 1 extra unit for every 10 grams of carbohydrate apart from your basal insulin. Although, this can vary from individual to individual based on their insulin sensitivity. So always consult a doctor to determine how many insulin units are required for you as basal and bolus insulin.

Reference: Updated on by Dr. Damanjit Duggal 


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