Administration of insulin


Are all insulins the same? 

No. You may be prescribed 1 or more types of Insulin. If you have Type II diabetes, then normally your body makes insulin all day, but increases production at mealtimes. Therefore, you may need a long-acting insulin and a short- or rapid-acting insulin. Talk to your doctor and pharmacist to determine what type you need to use.

Why is insulin available only as an injection?

Insulin cannot be taken in a tablet form. If we swallowed insulin the digestive enzymes in our stomach would break it down before reaching our bloodstream. Therefore, at this time, all insulin must be injected into our body. It is most commonly given as an injection directly under the skin. Certain types of insulin are injected in the vein but this must be done by a doctor or nurse.

Insulin can be supplied in different ways. These options include an insulin PUMP, an insulin PEN, or an insulin VIAL. Some patients use an insulin pump that injects insulin under the skin.


Types of devices used for administering insulin:




Use same area for injections.

  • If you inject into thigh, always use thigh. OK to inject into right or left thigh.
  • If you inject into arm, always use arm. OK to inject into right or left arm.
  • If you inject into belly, always use belly. Inject at least 2 inches away from belly button.


Rotate sites

Rotating sites is very important. Why?

  • It can be painful to inject in the same site frequently.
  • Injecting in the same site can cause the skin tissue to become very hard.
  • Injecting in the same site can cause increase in fat tissue at that site. The fat tissue alters the body's ability to absorb the insulin. 

How much insulin do I inject?

The decision about what dose you need and the way in which it will be delivered to you is made on an individual basis by your health care team. You are a vital member of this team, so your input will also be considered. Several different factors are taken into consideration to decide what is best for you such as your age, lifestyle choices, preferences, visual acuity, manual dexterity, cost, and how comfortable you are with injecting yourself.

It may take some trial and error before a final dosing regimen has been decided. A "regimen" is a strictly adhered to therapeutic plan. This plan is basically a schedule of the type or types of insulin you will use, how and when you will use them, and at what dose/s you will use them. Different people will have different regimens.

How is insulin dosed?

The measurement used to describe the dose of insulin is referred to in UNITS. The doctor will give you a prescription with the number of UNITS of insulin you need to inject and the time of day to inject.

Whether your insulin is in a vial, pen, or pump, you will notice that more units are in the device than what you will actually need each day. Each device will state how many insulin UNITS are in the entire volume of the device. The liquid volume of insulin is referred to in milliliters (mL). The amount of units in each milliliter (mL) is called the concentration. Concentration is the measure of how much of a given substance there is mixed with another substance. With some exceptions, the standard concentration for all insulin is 100 units of insulin for every 1 milliliter of volume. This is often referred to as U-100.

The other type of insulin concentration that is available in the United States comes in a VERY HIGH concentration. This insulin will deliver 500 UNITS in 1 milliliter (mL). It is often called U-500. This concentration is RARELY prescribed and should not be used unless discussed thoroughly with your doctor and pharmacist. 

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