Everything You Should Know About Injecting Insulin – A Guide

Posted by Prescription Hope - See Editorial Guidelines (Last Updated On: Fri Apr 21 2023)

Anyone who has type 1 diabetes and some patients with type 2 diabetes will require insulin therapy. Injecting insulin for some individuals may be a daunting task, especially if you are newly diagnosed with diabetes. Before discussing all of the details around injecting insulin, here is a quick summary of what you should know. What you should know about injecting insulin: You can inject insulin in three different ways – a syringe, a pen, or a pump. The method by which you inject insulin highly depends on your personal preference. However, there is a right way to inject insulin, and injecting insulin improperly may result in uncontrolled blood sugars. In this article, we’ll discuss everything you need to know about injecting insulin.

Ways Insulin Can be Administered

Everything You Should Know About Injecting Insulin Injecting insulin is the most common way of administering the medication. However, there is an insulin that can be inhaled. It is not as popular, but individuals may benefit from inhaling insulin if they have injection site reactions often. The only inhaled insulin on the market is Afrezza. There are three ways that an individual can inject insulin. They consist of using syringes with a vial, an insulin pen, or an insulin pump. The way one decides to inject insulin is highly dependent on personal preference and lifestyle factors. Your doctor may make a suggestion based on your current blood sugar control. However, some individuals find pumps to be the most beneficial for them, whereas some dislike having an insulin pump attached to their body. It is important to note that when you inject insulin using a syringe or a pen, you should hold the needle in place for 10 seconds after fulling injecting the dose. This ensures that you receive the full dose needed. Regardless of the method for injecting insulin that you use, your doctor should provide you with proper training on how to inject.

Injecting Insulin with a Syringe

An insulin syringe has four parts, which consist of the cap, the needle, a barrel, and a plunger. The cap is simply used to cover the needle for protection. The barrel is the portion of the syringe that holds the insulin once it is taken from a vial. The barrel of the syringe has markings on it to measure the dose of insulin. The plunger component fits perfectly inside the barrel of the syringe. It slides up and down to draw insulin into the barrel and to push insulin out through the needle. A rubber seal is at the bottom of the plunger to prevent insulin from leaking out of the syringe. The table below is a size chart for insulin syringes. You should use the smallest syringe size possible for the dose you need. Injecting Insulin

Injecting Insulin with a Pen

An insulin pen has the appearance of a large writing pen. Most insulin pens contain 300 units of insulin. At one end of the pen is a dial that is used to measure your dose by either 1 unit or ½ unit increments. At the other end of the insulin pen is a place where you have to screw on a small pen needle, which comes as a separate component. Once you have the needle placed on the pen and have dialed up your correct dose, you then push down on the plunger. After you have fully injected the insulin, recap the needle, and unscrew it from the pen. Dispose of the capped needle into a sharps container and place the cover back on the insulin pen.

Injecting Insulin with Pumps

Most insulin pumps generally work in a very similar way when it comes to injecting insulin. The specifics and look of the insulin pump will vary, depending on which one you use. A pump differs from the other two methods of injecting, as it provides a continuous delivery of short-acting insulin. The pump also replaces the need for multiple injections every day. Most insulin pump infusion sites need to be changed every 48-72 hours. When injecting insulin with an insulin pump, you first have to fill the pump cartridge or reservoir. This is done by using a syringe and vial. There is tubing that connects to the reservoir, and insulin travels through the tubing and into the subcutaneous tissue. The tubing may also be called a cannula.

Preparing Your Injection of Insulin

Diabetes is, perhaps, the only condition where the patient has to self-dose and administer their medication. So, when preparing your dose of insulin, you must ensure that you are giving yourself the correct amount of insulin based on your carb consumption and your current blood sugar reading. Everything You Should Know About Injecting Insulin Therefore, you must check your blood sugar often and before giving yourself insulin. When giving a mealtime dose of insulin, you should be counting carbs. This means utilizing your insulin to carb ratio to determine your full dose. You should not give yourself a mealtime insulin injection if you are eating to correct hypoglycemia. When preparing a correction dose, you must know what your correction factor is. A correction factor is how much one unit of rapid-acting insulin will reduce your blood sugar. A correction bolus should never be given if your blood sugar reading is at or below your target range. If a correction is needed before a meal, then your correction dose should be added to your meal bolus. There are times where you should not prepare an injection of insulin for a correction. These times include if it has been less than three hours since your last meal, less than one hour since exercise, or right before going to bed unless otherwise specified by your doctor.

Timing Your Injection

The timing of your insulin injection will depend on which insulin you are using, your blood sugar reading, and the type of food you are eating if this is a mealtime bolus. Most rapid-acting insulins start working within 15 minutes and peak at about 2 hours. Fiasp is insulin that advertised as entering the bloodstream in under 3 minutes, which means it starts working faster. Therefore, if you are prescribed Fiasp, then your insulin injection can be given right at the start of a meal or up to 20 minutes after starting. However, for other rapid-acting insulins, it is recommended that the timing of your insulin injection be given 15-20 minutes before starting your meal. If your blood sugar is low, then wait until you have started your meal before giving your bolus. You may also want to lower your mealtime bolus to prevent low blood sugar from occurring again after the meal. The timing of injecting insulin will help improve blood sugar levels after eating.

Using Two Types of Insulin

Many of those with type 1 diabetes may use two different types of insulin – long-acting and rapid-acting. If you are using an insulin pump, then the continuous delivery of insulin from the pump replaces the need for a long-acting insulin. However, if you do multiple daily injections a day, then you more than likely require more than one type of insulin. It is crucial that you never mix up the two types of insulins. When using insulin pens, the pens will, generally, be very distinguishable. They will be different colors with different names clearly printed on the pen. When using syringes for injecting insulin, the two different insulins will come in vials. They may be hard to distinguish than pens. Always double-check the label on the vial to ensure you are injecting the right insulin. Long-acting insulin should be administered at the same time each day. The time you perform this injection will vary depending on your lifestyle. Some individuals inject their long-acting insulin first thing in the morning, and others prefer giving it in the evening.

Rotating Injection Sites

When it comes to injecting insulin, you must rotate your injection sites. Continually injecting in the same spot can result in scar tissue. Scar tissue can cause painful injections and slow absorption of insulin. Insulin should be injected into fatty areas of the body. The most common injection sites include the abdomen, upper arm, buttocks, lower back, and thighs.

Injecting Cold Insulin

Insulin that is not being currently used should be stored in the refrigerator. Most vials or pens of insulin that are in use can be stored at room temperature for up to 28 days. Read the information insert that came with your insulin for proper storage. However, there are times where you forget to take insulin out of the fridge before needing it, which means you may need to inject cold insulin. So, what are the effects of injecting cold insulin? Injecting cold insulin may be more painful or uncomfortable than using insulin that is at room temperature. If you are preparing a cold insulin injection, then it may be more difficult to remove all air bubbles. Air bubbles can affect the amount of insulin you are getting from your dose, which then affects your blood sugar levels. If your insulin become frozen by being exposed to extreme temperatures, then you should not use it.


We hope this has given you a greater understanding of injecting insulin and which method of injecting insulin may be right for you. For questions regarding your specific condition and treatment, consult your healthcare provider. If you are having trouble affording your insulin or other prescription medication, then Prescription Hope may be able to help. The team at Prescription Hope works with pharmaceutical companies to provide individuals with their needed medication at a set, affordable price. Enroll with us and pay just $60.00 a month through Prescription Hope’s medication access service for each of your medications.