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Surprisingly Easy Way You Can Understand Insulin Syringe Types

Afraid to inject yourself with insulin, knowing the different insulin syringe types will help to ease a bit of your fear.  Insulin is an important part of diabetes care.  There is no need to be worried to inject yourself.  

There are different sizes of insulin syringes.  Usually the smaller needle will be less painful though if you are searching for insulin needles then let this be your guide to choose the right one. 

Choosing the right needle size isn’t the only way to improve your experience when injecting insulin.  Understanding where to inject insulin and the best practices to prepare that site is important too for your comfort.  

Not only that but dealing with sharp needles means you need to store it in a safe place.  Properly disposing of insulin syringes is very important.  

With that in mind, stay open to all the options available. Read on to learn everything you need to learn about insulin syringes to be successful along your diabetic journey.  

What Are Insulin Syringes?

Insulin syringes are long hollow tubes with a needle at the end.  These syringes are used to pull insulin from its vial.  Then the syringe can be used to inject the insulin into your body to help lower blood sugar levels to the correct range.   

Different Types of Insulin Syringes:  

There are many different sizes of insulin syringes.  When you order a box of insulin syringes there will be 3 words to pay attention to: gauge, length and unit size.   


Gauge refers to the thickness of the needle.  A smaller gauge means the needle is thicker while a smaller gauge means the needle is thinner. 

 Look for larger gauges as they are associated with less discomfort as you inject yourself with insulin (1).  A 27 gauge insulin pen will have a thicker needle while a 31 gauge insulin pen will have a thinner needle and usually cause less pain when injecting insulin. 


The length refers to how long the needle is.  If you see ½ inch or (12.7mm)  on the box then that means the insulin syringe needles are a standard size. 5/16 or (8 mm) refers to a short needle size.  A needle length of 3/16 or (5 mm) refers to a mini needle size. 

Please check your blood sugar constantly as the size of the needle could affect your blood sugar management.  For people with diabetes who are overweight or obese a short or mini needle size may not be long enough for the insulin to be absorbed when injected.    

Needle Length 

Standard ½ inch (12.7mm)

Short- 5/16 inch (8mm)  

Mini 3/16in (5mm)

Unit Size

The insulin box will also say U100, U30 or a different number.  This refers to the amount of units that you can hold insulin.

A needle of U100 can hold up to 100 units of insulin.  A needle size of U30 will only hold 30 units of insulin.  If you are unsure how much insulin units you need for a meal then check out this previous blog post.  

 Choosing The Right Type of Insulin Syringe

The insulin syringe type you chose to buy depends on a few different factors.  Ideally, you would choose one that is comfortable for you and doesn’t provide much pain. Everyone is different so choose one that works best for you.  

You also need to determine if the needle size is affecting your blood sugar levels.  Start with a standard needle size.  If you choose to try a short or mini size to minimize discomfort then always check your blood sugar 2 hrs after a meal.  

If the blood sugar is constantly high after injecting insulin with a short or mini needle then go back to a standard size needle.  If that does the trick then stick with a standard needle size.  

Another consideration is how much insulin units do you take in a day and how much do you take at a time.   If you inject 20 units of insulin before a meal then consider purchasing a U30 syringe.  However, if you take over 50 units of insulin then consider purchasing a U100 syringe.  

Can I Reuse Insulin Syringes? 

Once you have determined what kind of insulin syringe you want to purchase then you might be wondering if you can reuse an insulin syringe.  

The technical answer is no.  Don’t reuse your insulin syringe, it increases your risk for infection.  

If you do decide to reuse it then remember to clean the tube and plunger of the syringe with alcohol before each use. Also, please recap it after use and store it at room temperature. 

Remember that reusing insulin syringes can dull the needle which can make the injection more painful.  

How To Inject Insulin With An Insulin Syringe

If you are unsure how to safely inject insulin then follow these steps below.  

  1. Clean your hands
  2. Use alcohol to clean the injection site and the rubber top of the insulin vial
  3. Next draw air into the syringe 
  4. Then stick the needle into the rubber top of the vial
  5. Push the air from the syringe into the vial without removing the syringe 
  6. Now slowly draw the insulin into the syringe 
  7. Check for air bubbles.
    1. If you see air bubbles then push the insulin back into the vial and repeat again until no air bubbles are seen. 
    2. This is important because if you inject yourself with insulin full of air bubbles, then you do not have the correct amount of insulin in the needle.  This will result in an improper dosage which can affect your blood sugar management.  
  8. Then check to make sure you have the right amount of insulin in your syringe
    1.  The black rubber in the syringe should be in line with the amount of insulin units you plan to inject
  9. Gently pinch some  fat from your injection site
  10. Insert the needle and inject 
  11. Remove the needle after waiting for 5-10 seconds 
    1. Insulin can leak out if the needle is removed right away 
    2. Do not massage skin after injection 

Where To Inject Insulin Using An Insulin Syringe 

Now that you know how to inject yourself with insulin, you might be wondering where can I safely inject myself. Remember to inject into the fat layer and never the muscle as the insulin will absorb too quickly.   

Below is a list of where you can inject insulin safely:

Back of upper arm 

Outer part of thigh

Outer part of buttock 


Rotate your injection site every 2 weeks to prevent scar tissue build up.  It is also best practice to inject in the same area every 2 weeks but not in the exact same spot for those 2 weeks.   

How to Dispose of Used Insulin Syringes  

Now that you are done with the needle, you can place it in a disposable sharps container. These containers will be red and have an area to safely store the sharp needles. Ask your doctor for a sharps container.

If you don’t have a sharps container, don’t have money to buy one, or decide to DIY it then make sure to use a thick plastic container like an old bleach bottle or an old dishwasher liquid bottle.  Though if you do DIY an old container to be a sharps container then make sure it is clearly marked as a sharps container.  

After your sharps container is all full of needles then please return it back to your doctor’s office where they can safely dispose of them.  Hospitals are another place you can safely dispose of all your sharp needles. Feel free to call ahead of time to double check that you take your sharps there to dispose of them.   

Regardless of where you go to dispose of your sharp needles it is very important that you DO NOT throw it away in a regular trash can or in the recycle bin.

Final Thoughts 

Choosing the right insulin syringe type depends on many different factors.  Determine how much insulin you plan to inject yourself with during the day to make sure the syringe can hold it all.  Then determine how long you want the needle to be and how thick.  

A higher gauge or thinner needle is usually less painful and the way to go.  Consider starting out with a gauge of 31 and a ½ (standard) needle size.  Then adjust until you find the syringe that works best for you. 

When injecting insulin remember to be safe.  Clean your insulin top and your skin with alcohol to kill off any bacteria to make your injection safe. Also try to rotate where you inject insulin to decrease scar tissue build up.  

Finally, please dispose of your needle in a sharps container.  Then when the container is full take it to a doctor’s office or a hospital to have it disposed of safely.

Everyone has a different preference for syringe types.  Comment below on the type of syringe you like to use to inject yourself with insulin.    

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