Insulin Needle and Syringe Size Essentials: Three Common Sizes

Posted by medonthego on 2/13/2023 to

If you have diabetes, you’re likely familiar with how important it is to find the right types of syringes and needles to administer your medication. But did you know that Insulin syringes come in three different sizes?

The standard sizes include 1ml, 0.5ml, and 0.3ml—and each syringe size is used for different and distinct purposes. Knowing which size is right for your specific need can make all the difference in your injections being comfortable, safe, and effective.

Let’s review the different sizes of diabetes syringes and needles available, outline the pros and cons, and go over why you may need one over another. Review tips to help ensure your safety and successful injections every time you administer an insulin shot.

What Should Diabetes Patients Know About Using a Needle and Syringe?

Insulin syringes are meant for one-time use. This keeps the needles sterile and reduces the chances of infection. However, to avoid complications like lipohypertrophy (abnormal fat accumulating under the skin), you must rotate the spot where you administer your injections. (This is often referred to as an injection site.)

Insulin is given just under the skin or as a subcutaneous injection, keeping the needle away from the muscle. This may affect your blood glucose or blood sugar level.

The size of the syringe you use depends on your insulin dosage. Doses vary, as your blood sugar levels may go up and down. The exact dosage you may be prescribed to take depends on your sugar levels, lifestyle, diet, any previous dosages, and comfort level with managing infections.

Insulin needles, like other medical needles, are relatively thin and are used to carry medication into your body or bloodstream. And, much like syringes, they are designed specifically for one-time use only.

Needles are used to administer injections directly into the skin or in intramuscular injections. Shots are best administered at an angle of 90 degrees to ensure minimum insulin leakage. A needle cuts through the skin and reaches between a fatty layer to inject the medication.

What’s The Difference Between Syringes and Needles?

Hypodermic needles, or simply needles, are the sharp, pointed part of a medical syringe and are used to help penetrate the skin to deliver a medicine’s dose into the body.

Conversely, a syringe’s purpose is to draw or pull the medication out of an insulin vial with the help of a plunger.

Both needles and syringes work alongside each other. Without one, you can’t use the other. In addition, both must work together to administer an injection successfully.

The three most common sizes of syringes used to administer insulin are:

U-100 insulin syringe: This is the most commonly used insulin syringe, with a maximum capacity of 60 units. It is used for U-100 insulin, meaning that each unit of insulin contains 100 units per milliliter (mL).
U-40 insulin syringe: This syringe has a smaller capacity and is used for U-40 insulin, which is more concentrated and contains 40 units per milliliter (mL).
U-30 insulin syringe: This relatively new insulin syringe has the smallest capacity, with a maximum of 30 units. It is used for U-30 insulin, an even more concentrated form of insulin that contains 30 units per milliliter (mL).

An important note: Everyone’s insulin needs are different, and the type and size of the syringe any patient should use varies. It’s always best to first consult with a healthcare professional to determine the correct type of insulin and syringe for your needs.

What Do You Need to Know About Needle Length, Needle Gauge, and Barrel Sizes?

Insulin syringes are available in several sizes and help deliver various insulin doses. The number line visible on an insulin syringe measures the dose quantity in millimeters (mL).

The following size chart outlines standard insulin syringes and gauge and barrel size:

Common insulin syringes size chart

Length Gauge Barrel

5mm 28 0.3mL

8mm 29,30 0.5mL

12.7mm 31 1.0mL

The size of needles is measured using two factors: needle gauge and length. The gauge part provides information on the thickness and thinness of the needle. A diabetes patient may find that thin needles are beneficial when a smaller portion or dosage of medication is required.

The insulin syringe needle length determines how deeply it can penetrate. A syringe will only go into the layer of fat and not muscle, so the length isn’t too long.
The barrel size indicates how much insulin a syringe can hold.
And the gauge determines the thickness of the needle size (apart from the needle length).

The doctors recommend using a needle length between 4 and 6 millimeters. However, if the needle size is longer than that, it can pierce through the skin deeply, leading to several issues.

An important note: A thinner needle is generally more comfortable for most people, but a thicker needle administers insulin more quickly.

What Size Syringe Should You Use?

Insulin syringes are available in various sizes and different needle lengths from most medical supply stores and pharmacies that sell diabetes supplies. But how do you know what size is right for your health needs and medication dosage?

The size of the insulin syringe you should use depends on several factors, including your insulin dose, the type of insulin you use, and your preference. For many patients, using a short and thin needle translates to a more comfortable experience. However, if the needle is too long, the chances of a painful intramuscular injection may increase, resulting in severe complications.

There are three things to consider when deciding which size of insulin syringe you should use:

Insulin dose: Insulin dosage plays an important role in determining the size of the syringe you should use. For example, if you take a small insulin dose (less than 30 units), a smaller syringe with a capacity of up to 30 units may be more appropriate. On the other hand, if you take a larger insulin dose (more than 60 units), a larger syringe with a capacity of up to 60 units may be more appropriate.

Additionally, the size of the insulin syringe you use will vary, depending on how many different insulin doses you need throughout the day. For example: To maintain optimal health, if you require a shot of 45 units of insulin in the morning and 55 units at night, you will need both a 0.5mL syringe and a 1mL syringe, respectively, for each dose.

Tip: If your dosage is adjusted daily based on your blood sugar level, syringes may allow you more flexibility. And, if your dose is closer to the maximum capacity of the syringe, going for a size-up is usually a better idea.
Type of insulin: The type of insulin you are using will also determine the size of the insulin syringe you should use. For example, if you are using U-100 insulin, a U-100 insulin syringe with a maximum capacity of 60 units would be appropriate.
Personal preference: Some people prefer to use a smaller insulin syringe for a more precise dose, while others prefer a larger syringe for a faster and more convenient injection.

Why Is The Length and Gauge Of An Insulin Syringe Important?

When administering regular insulin injections, you should choose the syringe gauges and lengths you find most comfortable. The length of the needle is typically measured in millimeters (mm) and ranges from 4 to 12 mm. A longer needle may be more appropriate for people with thicker skin, while a shorter one may be more appropriate for those with thinner skin.

The gauge of the needle is a measure of its diameter, with a lower number indicating a thicker needle. Common gauges for insulin syringes range from 29 to 31 gauges. A thicker needle (lower gauge) is typically used for people with thicker skin or a higher amount of body fat. In comparison, a thinner needle (higher gauge) may be more appropriate for people with thinner skin or less body fat.

Many people prefer using shorter needles instead of thicker ones, according to a 2020 study. Several studies suggest that body mass index, or BMI, doesn’t affect insulin’s efficacy or potential leakage while using shorter needles. In most cases, people are advised to use needles ranging from 4-8 mm.

How Do You Properly and Safely Inject Insulin?

Nearly 24% of people who experience diabetes require insulin. However, since this medication is only available in liquid form, the best way to administer it is through an injection into the skin or tissue.

To inject insulin safely and effectively, follow the step-by-step guide:

Prepare your insulin syringe.

First, remove the caps from both ends of the syringe, and take extra care with the cap covering the needle. Next, pull back the plugger and draw some air into the syringe. Draw equal units of air as the amount of insulin dose is required.

Prepare the insulin flask or vial.

Put the insulin bottle upright and push the syringe into the vial. Inject the air into the vial and fill the syringe with the appropriate insulin dose. If you have cloudy insulin, roll the vial gently between your palms to ensure it gets thoroughly mixed.

Draw the insulin into the syringe.

Invert your insulin vial and push the needle into the vial. You should ensure that the end of the syringe’s needle is surrounded by insulin and not coming into contact with air. Draw in as many units of insulin as your prescription dictates.

Remove any potential air bubbles.

After filling the syringe with the right dosage of insulin, the next step is to remove bubbles. Hold the injection vertically and tap the syringe with a fingernail and finger. Keep pulling the plunger until the required number of units is filled. Remove the syringe, and repeat the above step if any air is left.

Prepare the injection site.

The appropriate place for injecting insulin is a soft and fatty area in the body, like the belly, thighs, buttocks, or arms. After you’ve cleaned and sanitized your injection area, gently pinch a small fold of skin between your fingers to prepare for the shot.

Inject the insulin.

Inject the needle into the fold of the skin, making sure that you maintain a safe angle. When the needle is penetrated fully into the skin, inject all the insulin slowly and steadily, pushing the plunger downward. Hold the needle for at least 10 seconds after injecting insulin.

An important note:

Wait to remove the needle until all of the insulin is injected. This helps to prevent any potential insulin leakage.

How Should You Dispose of Your Syringes?

Once you’re done using your insulin syringes, you’ll need to dispose of them safely. There are several safe ways to dispose of used syringes, but the best way is to use a sharp disposal container. These are sturdy, usually opaque containers that can help prevent medicine leakage or residue from harming anyone in your household and prevent accidental puncture.

To safely dispose of your insulin syringes, follow these simple steps:

Remove the needle: Before disposing of the syringe, make sure to remove the needle and discard it separately. This will reduce the risk of injury to others.

Tip: Use a specialist needle clipping device to remove the needle from the syringe before disposing of it.

Place the needle and syringe in a sharps container: A sharps container is a specially designed, puncture-resistant container used to dispose of sharp medical instruments, such as needles and syringes.
Label the container: If you’re using a reusable sharps container, make sure to label it with the words “used sharps.” If you’re using a disposable sharps container, it should already have a label indicating that the package contents include medical sharps, and the handler should use extreme caution.
Store the container securely: Store the sharps container out of reach of children and pets. Take care not to overfill the container.

Tip: When it’s about three-quarters full, it’s time to replace it with a new one.

Dispose of the container properly: When the sharps container is full, contact your local waste management facility or healthcare provider to find out how to properly dispose of sharps containers in your area.

It’s important to dispose of insulin syringes and needles properly to reduce the risk of injury and disease transmission. If you have questions or concerns about how to dispose of your insulin syringes, talk to your healthcare provider, pharmacy, or local waste management facility.

What Else Should You Know About Insulin Syringes and Needle Size?

Around 34 million people in the United States have diabetes and rely on insulin to manage their glucose levels.

For people who inject themselves daily, the correct needle size and syringe can make a huge difference in comfort and convenience. Keeping blood sugar levels steady and safely and comfortably administering shots all depend upon the size of the syringe you use.

Whether you’re new to this whole experience or have been using insulin injections for a while, it’s essential that you are familiar with all the different insulin syringes available to you—and that you know how to use them safely. As you consider which insulin syringe to use and what type might be right for you, remember the information outlined within this article to help you match the dosages you need, your body type, and your comfort level with administering shots.

We highly recommend consulting your doctor or healthcare professional if you have any questions about syringe or needle usage. Your healthcare provider can best answer specific questions about syringe sizes, diabetes treatment, insulin dosages, or how to manage your insulin infusion therapy.